The start button on the project to build new nuclear power plants at Sizewell C in southeast England is about to be pressed, but up-to-date assessments of likely capital costs and completion dates are needed first, a debate in the House of Lords was told.

Lord Howell of Guildford, a Conservative, told the upper house of the UK’s parliament that the EPR technology planned for Sizewell C “has a most unfortunate history” in construction timing, costs and reliable operation.

He said the EPR at Olkiluoto-3 in Finland took 20 years to complete and is many billions over budget. At Flamanville-3 in France they are running 11 years late. “It is still not ready and is also €10 billion over budget,” Lord Howell said.