Parliament restoration report due before MPs
Options for the "major restoration" of the Houses of Parliament, which could cost more than £3bn, are to be considered by MPs.
The 150-year-old Grade I listed building is partly sinking, contains asbestos and has outdated cabling.
An Independent Options Appraisal (IOA) report, compiled by industry experts and due on Thursday, will set out scenarios for its refurbishment.
It is expected to include suggestions for Parliament's temporary relocation.
A report in 2012 warned that "major, irreversible damage" may be done to the building unless significant restoration work is carried out.
Another previous report concluded the cost of maintenance is such that if the Palace of Westminster, as the building is also known, was a commercial structure of no historical significance, it would be cost-effective to demolish it and rebuild using modern construction techniques.
Leader of the Commons Chris Grayling said last week the building was "a vital heart to our democracy".
"There are some interesting and difficult challenges ahead, some difficult decisions to take," he told MPs.
"But I would say to the House that instinctively I think it is important that this building remains consistently at the heart of our democracy and that we don't end up being forced to move somewhere else."
According to the BBC's Robin Brant, there have been suggestions that while a full restoration will cost at least £3bn, taxpayers may have to pay double that if MPs decide they want to stay while the work goes on.
One option would be to set up temporarily over the road, by moving to either the Methodist Central Hall or the Queen Elizabeth II Conference Centre.
Some have suggested MPs could relocate to Birmingham - or hold a touring parliament, our correspondent added.
The majority of the historic building was built in the 1840s and 1850s as a replacement for a previous amalgamation of buildings which burnt down in 1834.
However, the Westminster Hall section of the parliamentary estate was constructed in the 11th Century.
The Commons chamber was destroyed in the blitz in 1941 and after some debate it was decided that it should be rebuilt in exactly the same style after the war.
The entire building is now a World Heritage Site.
A select committee of both the House of Commons and House of Lords is expected to be formed to consider the findings of the IOA and make recommendations to members of both Houses.