Boris Johnson told MPs and peers must decide on potential move of Parliament to York

The Prime Minister last month wrote to the heads of the body responsible for £4bn repair works on Parliament, asking them to consider moving either MPs, peers, or both outside of London during the restoration process.

But the Restoration and Renewal Sponsor Body and Delivery Authority has now replied and said it is for MPs and peers to decide where they should sit and it will not form part of their review.

In a letter to the Prime Minister, sponsor body chief Sarah Johnson and delivery authority head David Goldstone said there are “constitutional implications” for moving MPs and peers outside London “which makes this a matter for both Houses to determine rather than for our review”.

“This option will not, therefore, be considered as part of the scope of the strategic review,” they said.

MPs and peers agreed in 2018 to a plan that would see both Houses move to temporary facilities near the existing site – a “full decant” – to allow essential repairs and upgrades to be made to the Victorian palace.

But amid concerns about the cost – estimated at almost £4bn in 2014 – a review of the plans is being carried out by the sponsor body.

The letter to the Prime Minister noted the “full decant” – rather than a partial move which would see peers and MPs vacate Parliament in turn – had been judged as the “quickest, cheapest and least risky delivery option”.

But the review will consider “whether circumstances have changed so significantly as to warrant reconsidering these options”.

A spokesman for Parliament’s restoration and renewal programme said: “The Houses of Parliament are falling apart faster than they can be fixed.

“As the Prime Minister made clear in his letter, the current situation is unsustainable given the serious risk of a major fire and the need to upgrade services throughout the building.

“The restoration and renewal programme was set up in law, accountable to Parliament, to tackle this urgent work and is currently reviewing how the programme is delivered.

“The option of locating Parliament outside London has constitutional implications, and as the speakers of both Houses have stated, this means it is a matter for both Houses to determine rather than for our review.

“In line with best practice, we remain committed to developing a business case that will set out in detail the options for restoring Parliament, including cost estimates and timescales.”

He added: "As the letter makes clear, we wrote to both Speakers to seek their view on whether York should be considered, and they stated that as the location of the Houses is a matter for Parliament, it does not form part of the Programme’s scope, and consequently would be inappropriate for us to explore further. This option will not, therefore, be considered as part of the scope of the strategic review."

The York Central site, to the west of York Station, has been mooted as a location which could be redeveloped to house parliamentarians.

But the suggestion to move peers North has faced criticism, with accusations of No 10 of wanting to “rid (themselves) of these pesky Lords”.

The leader of York council previously wrote to the PM backing the plan to move the Lords or civil service departments.

Liberal Democrat Keith Aspden, who has led York Council since last summer, said the city’s “excellent transport links, talented population and ambitious plans for the future” made it the “ideal place for a major Government relocation”. He said: “I look forward to working to ensure that promises made to level-up our region are delivered.”

He added: “Historically York has already been home to the seat of power in the 15th and 16th century with the Council of the North. Today York is an ambitious city, steeped in history and with many exciting prospects for the future.”