Cairn Energy, the UK-listed oil and gas company, has hardened its stance in its battle to secure the Indian government’s approval for its proposed $9.6bn sale of oilfields in Rajasthan, rejecting conditions being placed on the transaction.

The directors of Cairn’s Indian subsidiary on Thursday said they “cannot accept” any interference that might change the value of the sale of a controlling stake in the company to UK-listed Vedanta. They also said uncertainty surrounding the deal was beginning to have a material impact on the performance of the business, and cause a loss of momentum.