Parliament facelift could cost £7bn
The taxpayer faces a bill of up to £7.1 billion to stop the Palace of Westminster falling down unless MPs and peers agree to move out while the work takes place, according to a report.
A study by independent consultants has highlighted the appalling condition of Parliament - with potentially deadly fire risks, collapsing roofs, crumbling walls, leaking pipes, and large quantities of asbestos.
If politicians refuse to leave the building, patching it up to basic standards will take around 32 years and could cost between £4.9 billion and £7.1 billion.
Even if they relocate to another venue and allow renovation teams free run of the historic site, it will still need six years and an estimated £3.5 billion capital outlay.
The eye-watering sums were calculated by a team of external experts led by Deloitte Real Estate. The study itself and associated investigations have cost around £8 million.
In a move which could fuel public anger, the report suggests that MPs and peers could take advantage of the essential works to upgrade their offices and facilities.
They indicate that an extra outlay of around £400 million could mean:
:: The installation of a 10-storey lift to take MPs and members of the public up the Elizabeth Tower, which houses Big Ben;
:: Converting one level of a car park into a subterranean meeting and reception space with huge skylights;
:: Landscaping courtyards, erecting glass roofs over outside spaces, and stretches of glazed walls to ensure MPs' offices have natural light;
:: New kitchens, improved banqueting facilities and refurbishing the famous benches in the Commons and Lords chambers;
:: A dedicated Media Centre for interviews.
A joint committee of MPs and peers will now be formed to consider the choices, chaired by Cabinet ministers Chris Grayling and Baroness Stowell. The project is not expected to get fully under way until after 2020.
But there have already been strong reactions from politicians.
David Cameron said it was crucial to be "cost- effective", and Downing Street indicated that the Prime Minister would be studying the report over the weekend.
The premier's spokeswoman said: "Clearly the sums outlined seem to be very high, so we need to make sure there is proper scrutiny of value for the taxpayer."
Leader of the House Mr Grayling said he was "not warm" to the idea of relocating.
"My very clear view is this building is an important part of our national heritage and our democracy, and it must remain as such," he said during Business Questions in the Commons.
"I am not warm to the idea we should look to move elsewhere - nonetheless, we do have to face the challenges of making sure it is fit for the 21st century and that discussion will involve all members of this House."
Labour backbencher for Dudley North Ian Austin called for parliament to be temporarily moved to Dudley Town Hall - and other MPs have made similar bids for buildings in their area to be used.
However, Parliament's restoration and renewal director Dr Richard Ware said they had not considered sites outside London.
He said there would be significant challenges with being in a location away from government departments and support staff.
The 250-page report points out that there have only been ad hoc works on the Victorian Palace over the past six decades.
As a result, the mechanical and electrical infrastructure is "no longer fit for purpose", and the risk of a "catastrophic failure is increasing".
Recent examples of issues include a burst pipe flooding the Committee Room Corridor, part of the ceiling in the Lords Chamber falling on to the benches below, and fears over asbestos.
The paper says "fundamental renovation can no longer be avoided" to protect the Thames-side building - a key part of the "UK brand" - and provide safe and "decent accommodation" for around thousands of people who work in it.
The lower estimate for the capital outlay if MPs remain on site is given as £4.9 billion, the central forecast £5.7 billion and the higher end £7.1 billion.
The project would take between 25 and 40 years, with 32 years being the most likely.
There will also be higher operating expenses during the period, as the Palace will have to wait longer for improvements such as to make it more energy-efficient.
The other options involve a partial or full move out of the Palace, which would dramatically reduce the bill and allow work to be completed much more quickly.
A "rolling" decant, where Lords and MPs vacate their chambers in turn, would mean renovations cost between £3.6 billion and £4.8 billion - with the central estimate £3.9 billion. The project would take around 11 years, according to the report.
A full decant from the Palace would cost £3 billion to £4.3 billion - with the most likely figure £3.5 billion. The most likely timescale in that scenario would be six years.
The study says Parliament's heavily-subsidised catering facilities could be either closed altogether during that period or relocated along with politicians and staff.
The study warns of a "significant risk" that suitable buildings are not available for a relocation - although the publicly owned QEII conference centre nearby has been frequently mentioned as a possible fallback.
Such premises would have to be found in the "near future" even if work did not start before 2020, the report added.
Upgrading Parliament's facilities, rather than merely restoring it to a basic standard, would increase the costs by hundreds of millions of pounds.
Dr Ware said: "The Palace has reached a turning point in its history, with many features needing major renovation. These include antiquated heating, ventilation, water, drainage and electrical systems combined with extensive stonework decay, leaking roofs, corrosion and the need to improve fire containment. Even the intensive programme of urgent repairs carried out over the last five years is barely scratching the surface."