MINISTERS have rejected claims that their GBP10 billion tax raid on North Sea oil and gas would lead to the loss of thousands of jobs and cost billions in investment, after industry leaders warned of a "dramatic drop in confidence" in the sector.  appearing before the Commons energy committee yesterday, Lib Dem Energy Secretary Chris Huhne, below, and Tory Treasury Secretary Justine Greening insisted the effect on investment would only be "marginal at worst".  and Mr Huhne claimed that there would be an increase in jobs as a result of the whole tax package rather than the predicted loss of up to 30,000 jobs predicted by the oil and gas sector.  The ministers were giving evidence on Chancellor George Osborne's fuel stabiliser, which saw the cancellation of a 5p a litre increase and a reduction in duty of 1p.  To pay for this he increased taxes on North sea profits by 12 percentage points, equating to an extra GBP2bn a year.  The comments by the two ministers came after industry body Oil and Gas UK raised concerns to the same committee about a "dramatic drop in confidence" since the supplementary tax on production was lifted from 20 per cent to 32 per cent to fund a cut in fuel duty.  But giving evidence to the energy and climate change committee,