A leading nuclear industry body has warned that Britain's electricity supply could be hit if the Government leaves Euratom without new measures being put in place.

There could also be a "significant potential impact" on the new £18 billion Hinkley Point nuclear power plant, according to the Nuclear Industry Association (NIA).

Chief executive Tom Greatrex said the "clock is ticking" for ministers to determine the UK's future relationship with Euratom, which oversees nuclear safety in Europe.

The Government has faced cross-party criticism over its decision to withdraw from Euratom as part of Brexit.

Euratom is a separate legal entity to the EU, but is tied up with its laws and institutions, including the jurisdiction of the European Court of Justice (ECJ).

It has a permanent presence at the Sellafield nuclear site in west Cumbria, where debate about membership is being closely watched.

About 21 per cent of the UK's electricity is generated by nuclear reactors, which Mr Greatrex said could make it much more complicated for bringing in fuel outside Euratom.

He added that two-thirds of Britain's power generating capacity was coming to the end of its life between 2010 and 2030 - making a very challenging situation even more complex.

"There is a potential disruption factor there for existing and continuing supplies of electricity," the former Labour MP said.

"It's a very real potential disruption if you come out of Euratom and you don't have successful arrangements in place relatively quickly."

Today, a Lords committee will grill industry experts on how Brexit will affect the UK energy supply, with questions over continued access to the EU's internal energy market and Britain's ability to influence future policy.

Much of the maintenance work on Britain's existing fleet of nuclear reactors takes place when parts are shipped to Europe.

Mr Greatrex also said the NIA had made specific representations to ministers about the potential impact on Hinkley Point, which is now being built by state-controlled French energy firm EDF in Somerset.

Ministers have previously said they could pay EDF billions of pounds in compensation over Hinkley Point, including over a so-called "political shut down".

The NIA, which represents about 65,000 workers in the civil nuclear sector, has pressed ministers to continue with some form of membership of Euratom, or enter into a transitional period to avoid a "cliff edge" in regulation when Britain leaves the EU in March 2019.

A spokesman for the Department for Exiting the European Union said: "Leaving Euratom is a result of the decision to leave the EU as they are uniquely legally joined.

"Our exact future relationship with Euratom will be subject to the negotiations, but we have been clear that we want to maintain our mutually successful civil nuclear cooperation with the EU."