Uncertainty over the Government's energy policy risks creating an "investment hiatus" that will stall Britain's renewable sector, according to a survey by KPMG.  Three quarters of companies said they would have invested more in Britain over the past three years if regulation was clearer and more consistent. The Government infuriated backers of large-scale solar photovoltaic schemes in February when it reduced the agreed level of subsidies that they could earn.  The change - together with the Chancellor's unexpected windfall tax on North Sea oil and gas producers - has led senior executives at some renewable energy companies to complain that funding is harder to attract because of the perceived "sovereign risk" involved in doing business in Britain. a planned overhaul of the British energy market, and a pending subsidy review for renewable technologies this year, have added to the uncertainty.  Nevertheless, the UK is still regarded as the second-most attractive renewables market for European investors, behind Germany.  andy Cox, head of energy and natural resources at KPMG, said: "There is a feeling in the market that there is an investment hiatus because people are waiting to see what reforms the Government makes to the energy market and renewable subsidies. The top of investors' list of concerns for the UK is uncertainty."  The annual survey into the renewables sector also found that Europe was struggling to attract investment from asia and that it would have to rely on domestic investors to hit challenging green targets.