Bidders will need to state their ultimate plans for the merged entity and the repercussions of the deal for the various stakeholders at a much earlier date, in conjunction with their intention to make a firm bid, according to the proposals from the Panel's Code Committee.

Buyers will also need to spell out what will happen to the target's headquarters and research & development (R&D) operations and whether its entire workforce will be impacted, with potential changes to the mix of skilled and unskilled workers and full time versus part time staff.

Such plans -- whether they remain post-offer intentions or legally binding undertakings -- will need to be published in a separate report as part of Britain's effort to make bidders accountable for what they promise.

The proposals, which have been put out for consultation until Oct. 31, have already been welcomed by Business Secretary Greg Clark stressing Britain's "reputation for being a dependable and confident place in which to do business."

Additionally the new rules say that bidders must wait at least 14 days before announcing their plans to make a firm offer, thus extending the average time for targets to respond.

Earlier this year Unilever (>> Unilever) boss Paul Polman urged the British government to provide a level playing field for target companies, adding the UK Takeover Code should consider the interests of stakeholders beyond shareholders.

Unilever successfully fended off an unsolicited $143 billion (£105.93 billion) takeover attempt by Kraft Heinz (>> The Kraft Heinz Company) in February which sparked concern over the vulnerability of large UK-listed companies once Britain leaves the EU.

Prime Minister Theresa May has also pledged to protect critical infrastructure and wants her government to intervene in deals that could affect national security.

The government said it will set out further measures in the autumn to safeguard national security, while ensuring the UK remains open to free trade and inward investment.

(Reporting By Pamela Barbaglia; Editing by Keith Weir)

By Pamela Barbaglia

Stocks treated in this article : Unilever (NL), Unilever, The Kraft Heinz Company