The business lobby group said that recent amendments by MEPs to the draft EU Industrial Emissions Directive mean that power plants will need to undergo costly upgrades to comply with air pollution targets or close by 2016. That could lead to a quarter of the UK’s electricity generating capacity – up to 14 plants being forced to close early.

CBI is calling for power plants to be given until 2021 to prepare for the proposed changes, which will allow other low-carbon forms of energy to be built to replace the lost capacity and ensure a smooth transition.

John Cridland, deputy director general of CBI, said: “Businesses want to help cut air pollution, but this directive must be implemented in a way that doesn’t undermine the UK’s energy security.

“The timescales currently proposed by some MEPs are unrealistic and could lead to up to 14 UK power plants having to shut prematurely. Given that these plants are old and due to close in the 2020s, letting them run their course would allow for a smooth transition to new low-carbon energy sources and avoid creating a serious energy gap.”

The directive is being voted on by the European parliament’s Committee on Environment, Public Health and Food Safety in Brussels in early May. After the vote, negotiations will take place between the council and European parliament, before the directive is voted on in a plenary session in Strasbourg during the summer months.

The CBI is also highlighting another worrying aspect of the directive that it says will reduce the UK’s flexibility to decide how best to meet the air pollution targets in the most cost-effective way.