Millions of UK homes could face three-hour blackouts this winter, warns the National Grid, an act which hasn't been done since the 1970s.

This is set to be due to "extreme" gas shortages and reduced electricity imports from Europe.

In the case of this emergency plan, consumers in different parts of the country are to be notified a day in advance of three-hour blocks of blackouts in an effort to reduce total consumption by 5%.

In order avoid this, households are to be encouraged to save money and back Britain to use energy during off-peak hours. 

This can be done by using appliances during the evening or charging an EV at off-peak times.

The National Grid hope this service will be able to provide an extra 2GW, which is said to be enough to power up to 600,000 homes if a suitable number of companies and households partake.

If the nationwide forced blackout was to come to pass, it would be the worst of three possible scenarios and could be the only hope to cope with the worst global energy crisis in decades.

The other two possibilities could see energy operators rewarding people for charging their electric cars during off-peak times and the use of backup coal plants.

Operators have emphasised they are "cautiously confident" that there will be more than enough electricity and demands for businesses and consumers during these unprecedented times however, the uncertainty of the situation across Europe has led them to look at a variety of possible scenarios.

A government spokesperson has stated: "The UK has a secure and diverse energy system.

"To strengthen this position further, we have put plans in place to secure supply and National Grid, working alongside energy suppliers and Ofgem [Office of Gas and Electricity Markets], will launch a voluntary service to reward users who reduce demand at peak times."

The spokesperson also insisted that the UK is not dependent on Russian energy imports, as it has support from the North Sea gas reserves, imports from Norway, and via ports.

Energy regulator Ofgem added: "We have one of the most reliable energy systems in the world, and we are in a favourable position.

"However, it is incumbent on a responsible and prudent energy sector to ensure the right contingency measures are in place."