The UK is falling behind in efforts to acquire energy from renewable sources, an unpublished report from the Department of Energy and Climate Change has warned.

According to the Times, internal forecasts by the department suggest that the UK is on track to be sourcing just 5 percent of its total energy from renewables by 2020, significantly under the 15 percent European target which it has signed up to.

The information, which was made public thanks to the Freedom of Information act, revealed a "fundamental failure" of the government's climate-change policy, shadow energy minister Greg Clarke told the newspaper.

Currently, it is estimated that Britain derives two percent of its energy from renewable sources, making it one of the least green energy producers in Europe.

Mr Clarke told the Times: "This amounts to an admission that the government is going to fail not just marginally but abjectly.

"For the past ten years, we have lacked a credible and comprehensive energy policy. Labour's piecemeal approach is clearly not working."

In his recently announced budget, chancellor Alistair Darling announced subsidies for biomass and wind projects, although industry reaction to the new funding has been mixed.

According to government statistics, the total installed capacity of renewable energy projects in the UK was 5.7GW in 2007, up from 3.5GW in 2003.