He said work was ongoing to locate a fault six miles off the coast of Scotland and this could be something the size of a pinprick or a 10p piece.

BBC: Moyle electricity interconnector repairs could cost ?60m

The fault affected First Capital Connect and East Coast services through Cambridgeshire and Hertfordshire.

BBC: East Anglia trains: Ice affected electric line supply

Since the initial repairs were carried out last winter, another fault has developed in one of the cables on the seabed about seven kilometres from the Scottish coast.

BBC: Moyle interconnector: Repairs cost ?31m