Government claims that Britain already supports nearly one million “green-collar” jobs have been exposed as a sham after the figures were found to include workers in the North Sea gas industry as well as suppliers of wallpaper and animal bedding.

Britain’s Low Carbon Industrial Strategy, outlined yesterday by Lord Mandelson, claimed that the economy already supported 880,000 “low- carbon jobs” — a figure that he said was poised to grow by up to 400,000 by 2015 to more than 1.28 million. But a detailed breakdown of the figures obtained by The Times shows that they include an extraordinarily loose definition of the term.

About a third of the jobs (266,000), comprises workers in “alternative fuels” — a category that includes the production and supply of natural gas and liquefied petroleum gas (LPG), as well as nuclear power and conventional “green” fuels such as biodiesel, bioethanol and hydrogen.

John Sharp, of Innovas, a consultancy in Winsford, Cheshire, which was paid by the Government to produce the figures earlier this year, confirmed that this included thousands of workers on gas production platforms in the North Sea as well as petrol station attendants on forecourts where liquefied petroleum is dispensed and employees at gas-fired power stations.

The list also includes manufacturers of a bizarre array of products — everything from skylights to wooden pallets and noise insulation materials.

Figures supplied by Innovas showed that the 880,000 total included 207 jobs in the supply and manufacture of animal bedding, 90 providing equestrian surfaces and 164 in the recycling of footwear, “slippers and other carpet wear”.

Mr Sharp acknowledged that there were some “weird and wonderful” categories. “We try to capture as much of the supply chain as possible,” he said.

A spokeswoman for the Department of Energy and Climate Change claimed that Innovas had itself defined the methodology used in the report. “They are looking at the whole low carbon supply chain, not just at the end-energy production,” she explained.

Robin Oakley, climate change campaigner for Greenpeace, said however that the definition used by the Government seemed unfeasibly broad and that there was “no need for the Government to massage the figures” because it was unquestionable that the economic future opportunity in the low-carbon sector would be huge.

Yesterday Lord Mandelson said: “The Government is determined to ensure the economic and employment opportunities that this transition [to a low-carbon economy] offers to us.”

Ed Miliband, the Energy and Climate Change Secretary, said that the low-carbon economy presented “big potential” for economic growth and job creation.

But The Times revealed yesterday that a factory in Newport, Isle of Wight, which is Britain’s only significant manufacturer of wind turbines, will produce its last batch of seven-tonne blades this week. More than 600 people employed at the plant, and a related facility in Southampton, will be made redundant at the end of the month.

All 7,000 turbines that the Government committed itself yesterday to installing over the next decade will be manufactured overseas, mainly in Germany, Denmark and China.

By 2020, renewable energy sources will provide 31 per cent of Britain’s electricity, up from 6 per cent today, while nuclear’s share will fall to 8 per cent from current levels of between 15 per cent and nearly a quarter, depending on the variable output of nuclear plants.