Sirius Minerals : Publication of Prospectus and Circular

THIS ANNOUNCEMENT AND THE INFORMATION CONTAINED HEREIN IS RESTRICTED AND NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN OR INTO THE UNITED STATES, ANY EXCLUDED TERRITORY OR ANY OTHER JURISDICTION IN WHICH THE RELEASE, PUBLICATION OR DISTRIBUTION WOULD BE UNLAWFUL.

This announcement is not a prospectus and not an offer of securities for sale in any jurisdiction, including in the United States, Australia, Canada, Japan and South Africa.

Neither this announcement nor anything contained herein shall form the basis of, or be relied upon in connection with, any offer or commitment whatsoever in any jurisdiction. Any offer to acquire shares pursuant to the proposed Firm Placing and Placing and Open Offer will be made, and any investor should make his investment decision, solely on the basis of the information that is contained in the Prospectus published by the Company in connection with the Firm Placing and Placing and Open Offer.

3 November 2016

Sirius Minerals Plc

Publication of Prospectus and Circular

Sirius Minerals Plc (the 'Company')previously announcedon 2 November 2016 the details of a proposedFirm Placing and Placing and Open Offer. On 3 November 2016, the Company announced that it had completed the Bookbuild and had raised gross proceeds of approximately £370 million through the Firm Placing and Placing in connection with its Stage 1 financing requirements to begin the construction of its North Yorkshire polyhalite project.

Capitalised terms not otherwise defined in the text of this announcement have the meanings given in the Company's announcement of 2 November 2016.

Further to the announcements by the Company on2November 2016 and 3 November 2016, the Company announces that the UK Listing Authority has approved a Prospectus in relation to the Firm Placing and Placing and Open Offer. In addition, copies of a Circular in connection with a General Meeting of the Company, to be held at 11:00 a.m. on 24 November 2016 at De Vere West One, 9-10 Portland Pl, Marylebone, London W1B 1PR, United Kingdom, will be posted to Shareholders (subject to certain restrictions) as soon as practicable.

The Prospectus and the Circular will be made available in electronic form on the Company's website at www.siriusminerals.com, and will be available for inspection at the Company's registered office at 3rd Floor, Greener House, 68 Haymarket, London SW1Y 4RF, United Kingdom between the hours of 9.30 a.m. and 5.30 p.m. on any Business Day. The Prospectus will also be submitted to the National Storage Mechanism, where it will be available for inspection atwww.morningstar.co.uk/uk/nsm.

This announcement is released by Sirius Minerals Plc and contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 'MAR', encompassing information relating to the Firm Placing and Placing and Open Offer and the Stage 1 Financing described above, and is disclosed in accordance with the Company's obligations under Article 17 of MAR.

For the purposes of MAR and Article 2 of Commission Implementing Regulation (EU) 2016/1055, this announcement is being made on behalf of the Company by Tristan Pottas, Investor Relations Manager.

For further information, please contact:

About Sirius Minerals Plc

Sirius Minerals Plc is the fertilizer development company focused on the development of its North Yorkshire polyhalite project, the United Kingdom. It has the world's largest and highest grade deposit of polyhalite, a multi-nutrient form of potash containing potassium, sulphur, magnesium and calcium. Incorporated in 2003, Sirius Minerals Plc's shares are traded on the London Stock Exchange's AIM market. Further information on the Company can be found at: www.siriusminerals.com.

Important notice

Forward-looking statements

This announcement contains forward-looking statements, including but not limited to statements about the costs of, and the Company's ability to successfully construct, commission and execute, the Project. By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future and therefore are based on current beliefs and expectations about future events. Forward-looking statements are not guarantees of future performance and the Group's actual operating results and financial condition, and the development of the industry in which it operates may differ materially from those made in or suggested by the forward-looking statements contained in this announcement. In addition, even if the Group's operating results, financial condition and liquidity, and the development of the industry in which the Group operates are consistent with the forward-looking statements contained in this announcement, those results or developments may not be indicative of results or developments in subsequent periods. Accordingly, prospective investors should not rely on these forward-looking statements. The Company disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. None of the Company, the Directors, the Joint Bookrunners or the Co-Lead Managers undertake any obligation nor do they intend to revise or update any document unless required to do so by applicable law, the Prospectus Rules, the Disclosure Requirements or the Transparency Rules.

This announcement and the information contained in it is restricted and is not for release, publication or distribution, directly or indirectly, in whole or in part, in, into or from the United States (including its territories and possessions, any state of the United States and the District of Columbia, collectively the 'United States') or any Excluded Territory or any other jurisdiction where to do so might constitute a violation of local securities laws or regulations. The information in this announcement may not be forwarded or distributed to any other person and may not be reproduced in any manner whatsoever. Any forwarding, distribution, reproduction, or disclosure of this information in whole or in part is unauthorised. Failure to comply with this directive may result in a violation of the Securities Act or the applicable laws of other jurisdictions.

This announcement is for information purposes only and does not constitute an offer or invitation to sell or issue or the solicitation of an offer to buy, acquire or subscribe for New Ordinary Shares to or by anyone in any Excluded Territory or to any person to whom it is unlawful to make such offer or invitation or undertake such solicitation. Any failure to comply with these restrictions may constitute a violation of the securities laws of such jurisdictions. Subject to certain exceptions, the securities referred to herein may not be offered or sold in any Excluded Territory or to, or for the account or benefit of any national resident or citizen of any Excluded Territory. This announcement does not constitute an extension into the United States of the offer mentioned in this announcement, nor does it constitute nor form part of an offer to sell securities or the solicitation of an offer to buy securities in the United States. The New Ordinary Shares have not been and will not be registered under the Securities Act or under any securities laws or with any securities regulatory authority of any state or other jurisdiction of the United States. The New Ordinary Shares may not be offered, sold, resold, taken up, transferred, delivered or distributed, directly or indirectly, into or within the United States absent registration under the Securities Act or an available exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and in compliance with any applicable securities laws of any state or other jurisdiction of the United States. There will be no public offer of the New Ordinary Shares in the United States. The New Ordinary Shares may not be offered or sold to, or for the account or benefit of, any ADR Holder. Subject to certain exceptions, no action has been taken by the Company or by the Joint Bookrunners that would permit an offer of the New Ordinary Shares or possession or distribution of this announcement in the Excluded Territories or any other jurisdiction where action for that purpose is required, other than the United Kingdom. No public offering of the shares referred to in this announcement is being made in any Excluded Territory or elsewhere.

This announcement has been issued by, and is the sole responsibility of, the Company. No representation or warranty, express or implied, is or will be made as to, or in relation to, and no responsibility or liability is or will be accepted by the Joint Bookrunners or the Co-Lead Managers or by any of their respective affiliates or agents as to or in relation to, the accuracy or completeness of this announcement or any other written or oral information made available to or publicly available to any interested party or its advisers, and any liability therefore is expressly disclaimed.

J.P. Morgan Cazenove, which is authorised by the Prudential Regulation Authority (the 'PRA') and regulated in the United Kingdom by the FCA, and the PRA, and Liberum, Shore Capital and W.H. Ireland, each of which is authorised and regulated in the United Kingdom by the FCA, are each acting exclusively for the Company and no one else in connection with the proposed Firm Placing and Placing and Open Offer and Admission, and will not regard any other person (whether or not a recipient of this document) as a client in relation to the proposed Firm Placing and Placing and Open Offer or Admission, and will not be responsible to anyone other than the Company for providing the protections afforded to their respective clients, nor for providing advice, in relation to the proposed Firm Placing and Placing and Open Offer or Admission or any other matter referred to in this announcement.

Apart from the responsibilities and liabilities, if any, which may be imposed on the Joint Bookrunners and the Co-Lead Managers by the Financial Service and Markets Act 2000, as amended, or the regulatory regime established thereunder, or by the London Stock Exchange or the AIM Rules, or under the regulatory regime of any jurisdiction where exclusion of liability under the relevant regulatory regime would be illegal, void or unenforceable, none of the Joint Bookrunners and Co-Lead Managers, nor any of their respective affiliates, directors, officers, employees or advisers accepts any responsibility whatsoever for, or makes any representation or warranty, express or implied, as to the contents of this announcement, including its accuracy or completeness, or for any other statement made or purported to be made by it, or on behalf of it, the Company, the Directors or any other person, in connection with the Company, the New Ordinary Shares, the Firm Placing and Placing and Open Offer or Admission, and nothing in this document should be relied upon as a promise or representation in this respect, whether or not to the past or future. Each of the Joint Bookrunners and Co-Lead Managers and their respective affiliates, directors, officers, employees and advisers accordingly disclaims to the fullest extent permitted by law all and any responsibility or liability whatsoever, whether arising in tort, contract or otherwise (save as referred to above), which it might otherwise have in respect of this announcement or any such statement.

The distribution of this announcement and the offering of the New Ordinary Shares in certain jurisdictions other than the United Kingdom may be restricted by law. Subject to certain exceptions, no action has been taken by the Company, the Joint Bookrunners or the Co-Lead Managers that would permit an offering of the New Ordinary Shares or possession or distribution of this announcement or any other offering or publicity material relating to such shares or the Application Form in the Excluded Territories or in any other jurisdiction where action for that purpose is required. Persons into whose possession this announcement comes are required by the Company, the Joint Bookrunners and the Co-Lead Managers to inform themselves about, and to observe, any such restrictions.

Statements contained in this announcement regarding past trends or activities should not be taken as a representation that such trends or activities will continue in the future.

No statement in this announcement is or is intended to be a profit forecast or profit estimate or to imply that the earnings of the Company for the current or future financial years will necessarily match or exceed the historical or published earnings of the Company. The price of shares and the income from them may go down as well as up and investors may not get back the full amount invested on disposal of the shares.

The New Ordinary Shares to be issued pursuant to the Firm Placing and Placing and Open Offer will not be admitted to trading on any stock exchange other than on AIM, a market operated by the London Stock Exchange.

Neither the content of the Company's website nor any website accessible by hyperlinks on the Company's website is incorporated in, or forms part of, this announcement.