MPs on the energy select committee and several North Sea energy operators clashed with Government ministers over budget changes. The supplementary tax on North Sea oil production has been increased by 12 percentage points to 32 per cent, meaning some field tax rates are as high as 81 per cent. It is feared as many as 30,000 jobs could be lost because of a decrease in investment, while some warned the move could lead to more gas imports and higher domestic heating bills. It has emerged that oil majors from BP to Royal Dutch Shell have taken balance sheet hits of about $1bn because of the levy. Energy Secretary Chris Huhne refused to confirm whether he had been consulted about the rise, but he did announce that the Government would work with the industry to mitigate the impact of the tax.