LONDON, July 29 (Reuters) - The UK's Department for Environment, Food and Rural Affairs (DEFRA) said on Friday it has been directed by the government to temporarily relax permitting conditions for coal-fired power stations in England during the winter period.

"The direction is to...address energy security issues if they arise, whilst aiming to limit unnecessary pollution," it said in a statement.

The measure, which will be effective from Oct. 1 to March 31, comes as countries across Europe make winter contingency plans after Russia reduced natural gas flows and said supplies could be cut further or even stop.

Many European leaders have expressed a belief that Moscow's actions are a reaction to Western sanctions on Russia in response to its invasion of Ukraine.

Britain's National Grid said on Thursday there could be periods where electricity supply is tight this winter but that it expects to be able to meet demand.

Gas-fired power plants were responsible for more than 40% of Britain's electricity production last year while the fuel is also used to heat around 80% of British homes.

Operators of coal plants, such as Drax and EDF, have been running down coal stocks and preparing for closure. The government remains committed to a longer-term plan to close all of the country’s coal-fired power plants by October 2024 to help it to hit climate targets.

Separately, the government said that it will allow electricity generation sites in the UK, which have been given a limited life derogation (LLD), to operate until 30 September 2024, to address energy security issues if they arise.

(Reporting by Shanima A in Bengaluru and Marwa Rashad in London; Editing by Shailesh Kuber, Kirsten Donovan)