House of Commons backs full move of MPs and peers to alternative sites while multi-billion pound restoration takes place.
MPs have voted to move Parliament to another location for what is likely to be six years while a major restoration of the Palace of Westminster is carried out.
In a surprise move, the House of Commons narrowly rejected government proposals that would have delayed a final decision and instead backed a cross-party amendment in favour of a “full and timely decant” of Parliament.
Ministers had proposed setting up a new authority to assess whether Parliament should be completely moved while the work is undertaken or should continue to use part of the Palace of Westminster.
But MPs lined up to criticise the Government for delaying the issue and voted by 236 to 220 in favour of the move, which has previously been recommended by two parliamentary committees.
The vote marks the next step towards a comprehensive refurbishment of the Palace, which experts say is urgently needed.
It will mean alternative sites need to be found for the House of Commons and House of Lords. MPs are likely to move to Richmond House in Whitehall, currently home to the Department of Health and Social Care, while peers could use the Queen Elizabeth II conference centre just off Parliament Square.
Alternative options included a partial move, in which the Commons and the Lords moved one after the other, which would have cost £4.4bn over 11 years, according to a parliamentary committee that looked at the issue. Another proposal, costing £5.7bn over 35 years, would have seen both Houses remain on site while the work is carried out.
The move is unlikely to take place until 2025 and will require a full Act of Parliament before it is confirmed.
While voting in favour of a temporary move, MPs rejected an SNP amendment that said a review should consider whether Parliament should move away from Westminster permanently.
The cost of vacating the Palace of Westminster while work is undertaken is estimated at between £3.5bn and £3.9bn, depending on the extent of the works, analysis by accountants Deloitte found. That is cheaper than attempting to renovate the building while MPs and peers continue to use it.
Parliament houses 7,500 staff and plays host to more than a million visitors each year but some of its plumbing and electric cabling has barely been upgraded since the current building was completed in 1870.
Officials have previously warned that the Palace is at risk of a “catastrophic failure” such as a flood or fire because plumbing and electrical infrastructure is “no longer fit for purpose”.
Work is needed to install new piping and cabling, repair crumbling stonework, remove asbestos, restore 4,000 windows and repair damaged roofs.
Opening the debate, Andrea Leadsom, the Leader of the House, said: “The Palace of Westminster is the seat of our democracy – an iconic, world famous building – and it is in dire need of repair.”
While Parliament is “structurally sound”, it contains a number of “critical risks”, including fire hazards, she said, adding that there have been 60 incidents in the last 10 years that could have caused a serious fire.
Ms Leadsom said there is a “huge amount” of asbestos in the walls of the Palace and pipes and cables are “ageing faster than it is possible to repair them”, adding: “The likelihood of a major failure grows the longer the systems are left unaddressed.”
With all the options for the refurbishment running to several billion pounds, Ms Leadsom said: “We’ve been clear that there can be no blank cheque for this work and value for taxpayers’ money will frame the decisions we make.”
She added: “Keeping everyone safe is becoming a growing challenge with each passing year… that is the key point that we are seeking to resolve.
However, a number of MPs accused the Government of delaying the decision.
Meg Hillier, chair of the Public Accounts Committee, said failing to reach a verdict now would increase the cost of the project.
“If we make a decision with three options, and three options have to be fully worked up and fully costed, that is a considerable cost in time and taxpayers’ money,” she said. “To make a decision now will mean we can get on with it, make the path forward and make sure we can get value for taxpayers’ money.”
Tory backbencher Anna Soubry added: “The time for talking is over. We have got to grasp this and do the right thing.”
MPs should agree that Parliament must temporarily move while the work is completed, she said, joking that for the first time she would be encouraging colleagues to “vote leave”.