Treasury made oil tax 'pledge'
Treasury officials last year promised oil companies that the government would not impose a windfall tax on profits, it was reported at the weekend.
Oil giants threatened to slash North Sea oil investment if ministers opted for levies which they thought unfair, according to the Sunday Times.
Speculation that chancellor Gordon Brown might hit oil companies was prompted by results from BP, which reported a £5.6bn profit for the first half of the year.
Meanwhile, head of economics at business services firm Tenon, Maurice Fitzpatrick has said the chancellor could impose a 20% surcharge on North Sea oil taxation to finance a 3p cut in excise duty on fuel.