Vodafone India Ltd, the country's second-biggest mobile phone carrier by customers and revenue, is contesting at a telecoms tribunal government charges of about $1.1 billion for merging the businesses.

The Indian Supreme Court on Monday asked Vodafone for the $302 million as an interim payment, according to a lawyer on the case. The government will allow the merger process to proceed as soon as Vodafone deposits the money, the lawyer said.

Vodafone's final fee will depend the outcome of the case at the telecoms tribunal, the lawyer said.

Vodafone declined to comment on the case.

Vodafone has started preparations for a potential initial public offering of the Indian business, it said earlier this month.

(Reporting by Devidutta Tripathy and Suchitra Mohanty. Editing by Paul Sandle and Jane Merriman)