London, Nov 10 (IANS): In a setback to the fight against global warming, a new study has warned that Britain is set to miss key carbon emission cut targets, media reported Monday.

According to London's Imperial College, this would be the result of too many of the country's most polluting coal-fired plants staying open much longer than the government had pledged, The Independent reported.

While the government had said that it would make it so expensive for coal plants to operate that they would have no choice but to shut down within a decade, it has failed to do so, warns the report.

Ageing coal plants must be closed by 2025 if Britain is to get anywhere near its legally binding commitment to slash carbon emissions by 60 percent of 1990 levels by 2030.

The hugely inefficient coal plants from the 1960s and 1970s are a major source of carbon emissions in Britain.

If they are allowed to keep operating into the 2030s, it would be virtually impossible for the country to meet key emission cut targets.

The report's findings will leave questions over Prime Minister David Cameron's vow that his coalition would be the “greenest government ever”.

“The government is tearing up its green credentials and throwing them out of the window,” said Chris Todd, of the Campaign for Better Transport lobbying group.

“Britain is in danger of massively overshooting its carbon-emission target for electricity if we fail to close coal (plants),” said Jenny Banks, energy and climate change specialist at WWF, the environmental charity that commissioned the report.

Experts say Britain must reduce emissions from the power sector -- which make up nearly half of the country's total -- to one-tenth of today's level if it is to meet its climate goals.