Britain's National Grid said it would pay customers to use less power today and that it had asked for three coal-powered generators to be warmed up in case they are needed as the country faces a snap of cold weather.

The group said that it would activate a new scheme called the Demand Flexibility Service where customers get incentives if they agree to use less power during crunch periods.

The service, which has been trialled but not run in a live situation before, would run from 5pm to 6pm this evening, it said.

It added that the move did not mean electricity supplies were at risk and advised people not to worry.

The measures were announced in order to "ensure that everyone gets the electricity they need," Craig Dyke, Head of National Control at National Grid ESO, told BBC Radio this morning.

He added that 26 suppliers had signed up for the scheme.

Below freezing temperatures have been recorded across much of the UK in recent days with the national weather service, the Met Office, last week issuing severe weather warnings for snow and ice.

National Grid's Dyke said consumers could make small changes to make money by reducing their energy usage, such as delaying cooking or putting on the washing machine until after 6pm.

National Grid said in December that over a million British households had signed up to the scheme, which is one of its strategies to help prevent power cuts.

The announcement about the coal-powered generators did not mean they would definitely be used, it said in a separate statement.

UK coal-powered generators were last put on stand-by in December when temperatures dropped and demand for energy rose, but they were not needed on that occasion.