The government last night suggested that the UK would not source 20 per cent of its energy from renewable sources by 2020, but argued that this would not contravene EU targets on renewable energy as they applied to the union as a whole, and not individual countries.

Speaking on BBC's Newsnight, energy minister Malcolm Wicks said the UK would source up to 15 per cent of its energy from renewables by 2020, but insisted the government was not attempting to water down the EU's goal of generating 20 per cent of energy from renewables by the same date.

"We're negotiating with the European Commission, but it's got to be a considerable figure," he said. "It's got to be somewhere between 10 and 15 per cent."

He was speaking in the wake of reports in The Guardian newspaper that leaked documents from the Department for Business, Enterprise and Regulatory Reform (BERR) revealed that ministers were advising the prime minister to lobby for lower renewables targets before binding EU-wide agreements are made in December.

The documents argued that meeting the targets would face "severe practical difficulties" and advised Gordon Brown to join forces with countries sceptical about the EU's climate change policy to push for weaker targets.

A BERR spokesman said that the government was investigating how the EU target should be met, but insisted ministers are "not planning a U-turn on any of our pledges to combat climate change and the government is not seeking to 'effectively abolish' the target for renewable energy agreed by the European Union in the spring".

He added that BERR remained committed to the renewables industry and cited the recent approval of several large-scale clean energy projects as evidence it is working to increase the UK's renewable energy mix.

The news comes as the government also faced criticism for scaling back the budget for household energy efficiency programmes, such as the free insulation and energy advice services run by many local councils and energy companies.

Gordon Brown had committed £20m to such schemes in last year's budget, but according to figures released by Defra in response to a parliamentary question from Labour MP Linda Gilroy, just over a quarter of the promised funds have been delivered with much of the rest having being diverted into other projects, most notably a Carbon Trust scheme to fit wind turbines to public buildings and hospitals.