The report "UK Climate Change Programme -- Annual report to parliament, July 2008" said it expected emissions of CO2, the main climate warming culprit, to be 26 percent below 1990 levels by 2020.

"The government has clearly failed to take the action needed to meet its own targets for cutting the UK's carbon dioxide emissions," said Martyn Williams of Friends of the Earth.

"This unhappy situation is made even worse by the fact that these targets are out of date and massively underestimate the overall level of cuts that is needed."

The government has prided itself in taking a global leadership role in combatting climate change, taking strong measures at home and keeping the issue in the forefront of international negotiations.

But its Climate Change Bill that will set a legal target of cutting national CO2 emissions by at least 60 percent by 2050 is well behind schedule in the parliamentary process and recent reports have shown the government slipping from its own agenda.

The government has even admitted that it has been badly underestimating national emissions, noting that if carbon embedded in imports from China were included then far from falling they would actually have risen sharply.

A report issued by DEFRA ahead of last week's G8 summit in Japan said emissions of carbon dioxide (CO2) fell by 5 percent between 1992 and 2004.

But it said they actually rose by 115 million tonnes or 18 percent over the same period when the carbon emissions linked to imported goods were included in the calculation. (Editing by Douglas Hamilton)