One of the UK’s eight remaining coal power stations is expected to cease generating electricity this year, the government has said as it laid out new rules that will force all the plants to close by 2025.

The coal phase-out is one of the Conservative Party’s flagship green policies, and the long-awaited implementation plan comes ahead of a speech by Theresa May on the environment this week.

While three plants shut in 2016, and most are expected to halt operations by 2022, the last ones standing will be forced to close in October 2025 because of new pollution standards, according to The Guardian and Euractiv.com.

However, the plan reveals the sector will continue to be propped up by hundreds of millions of pounds in backup power subsidies for several years, paid through consumer energy bills.

Coal’s fall has been swift and dramatic, with power generation from the polluting fuel plunging by more than 80% since 2012.

Experts said allowing coal operators to continue receiving capacity market subsidies had thrown the sector an unnecessary lifeline.

The government rejected calls by campaigners and industry groups for the deadline of 2025 to be brought forward, citing cost and energy security grounds. It also rebuffed suggestions of a gradual phase-out before 2025, arguing coal use was low enough to make that unnecessary.