By Liz Stephens
The proportion of renewable energy used by government departments has actually dropped in the last year, according to the environmental audit committee (EAC).
The news could not have come at a worse time for ministers, who are currently attempting to position themselves as leaders on the world stage prior to the Copenhagen summit while facing accusations of failing to prevent the closure of the Vestas windfarm at home.
Chair of the EAC Tim Yeo strongly criticised the government, saying: "The government's enormous buying power should be used to drive the transition to a low-carbon economy and boost the number of people in green jobs.
'Because key gateways have been capacity constrained, a lot of freighter services now terminate in mainland Europe'
"Leadership on these issues is crucial - the government can't have one prescription for the country and another for its own operations."
Despite a well-publicised white paper, The Road to Copenhagen and its much-stated commitment to building a low carbon economy, the report says the government is failing to meet its own target of a 12.5 per cent reduction in carbon dioxide by 2010/11.
In fact, the committee warns the government's 'poor progress' on cutting its own carbon emissions may mean that it has to buy carbon credits from the private sector.
This could mean taxpayers have to pay under the carbon reduction commitment - a carbon trading scheme due to begin in April 2010 which was ideally envisaged to cover industry, not government, shortfalls.
With carbon allowances set at £12 for every tonne of carbon dioxide the emissions trading scheme could prove very expensive.
Mr Yeo warned: "Unless the government gets its house in order taxpayers could end up paying a heavy price to buy carbon credits from the private sector.
"Cutting government energy bills with better insulation, solar panels and new heat and power boilers could save us lots of money in the long run-but ministers have so far lacked the vision to invest for the future."
Liberal Democrat environment spokesman, Simon Hughes said: "This report shows the Government has failed to use its own enormous buying power to drive the change to a low-carbon economy and create jobs.
"The Government is failing to give the environmental leadership that Britain needs."
The EAC's suggestion that the government buy carbon credits has come under fire from environmentalists who claim carbon trading offers a back door for avoiding vital emissions cuts.
Friends of the Earth previously criticised the government for allowing the buying and selling of carbon 'credits' to offset emissions in their 'Road to Copenhagen' manifesto.
Andy Atkins, executive director of the organisation said: "Continued support for offsetting through expanding carbon markets will neither tackle climate change nor set Britain on a low carbon path to new green jobs and industries."
The bulk of the carbon emissions are caused by poor energy use in government buildings.
Emissions from government offices have been reduced by only 6.3 per cent since the baseline year of 1999-2000.
Adrian Harvey, head of public affairs at the government's built environment watchdog CABE, said: "Central government is a significant property owner and manager.
"This provides an excellent opportunity to demonstrate leadership on energy efficiency as part of their work to meet wider targets and commitments.
"Part of that leadership role should be to make a public commitment to improving the energy efficiency of their properties in Whitehall by a minimum of one rating in the next year."
He also highlighted the fact that it wasn't only old government buildings that were "underperforming".
The UK was the first country in the world to set legally binding targets for greenhouse gas reduction in the Climate Change Act of 2008.