MULTI-BILLION-pound proposals to refurbish the UK Parliament building have been condemned by the SNP as “eye-watering” during a time of public spending cuts.

The Palace of Westminster, largely constructed in the middle of the 19th century, has been hit by decaying stonework and subsidence and also contains asbestos and electric cabling, according to a report commissioned by parliamentarians last year.

But as MPs and peers prepare this spring to recommend an option to take forward the work, which could cost up to almost £6 billion, the SNP have called for a rethink.

“The cost of restoring Westminster is astronomical," said the MP Tommy Sheppard. "The prospect of spending billions of pounds at a time of belt-tightening and damaging Tory austerity is eye-watering.

“The people coming up with these proposals must live on another planet if they think it will wash with the public. Nothing damages the reputation of parliament and politics more than the establishment being seen to look after itself while services and social security for the majority are savaged.”

Sheppard, the SNP’s Cabinet Office spokesman, also hit out at the fact the Joint Committee is not considering a move to a newbuild parliament, which he believes could have prompted a much-needed modernisation of working parliamentary procedures and practices.

“The decision by the Joint Committee to rule out a newbuild parliament means the UK Parliament will remain crowbarred into an expensive, impractical and archaic building whatever the cost to keep it going,” he said.

“This should also be an opportunity to reform and modernise the way business is conducted in the Houses of Parliament. It could have been a golden opportunity to look at the way politics works at Westminster and a way to modernise the antiquated and outdated way this building actually works but the costs are based on a “like for like” refurbishment, meaning we would still have the House of Lords and all the Victorian working practices that might have worked in 1916 – but certainly don’t in 2016.”

He added: “This cannot become another Westminster stitch-up decided behind closed doors with little or no public awareness or consultation. There needs to be clear lines of accountability and scrutiny at all stages so this doesn’t spiral out of control.

“Unfortunately, this is part of the cost to Scotland of remaining under the Westminster system. If we are to spend untold billions, we expect – at the very least – to see a parliament fit for the 21st century.”

The SNP’s submission will now be considered by the Joint Committee, which is due to decide which option to recommend before the matter goes to a vote.

Last year, an Independent Options Appraisal (IOA) report for the committee set out a range of scenarios from a "do minimum" gradual approach, to making significant improvements in a single phase.

It found that a rolling programme, involving gradual work with the Parliament remaining in occupation, would take about 32 years. During that period both Chambers would have to close for two to four years, at different times, but sittings could be relocated to a temporary structure elsewhere in or around the Palace.

It said occupants would have to tolerate high levels of noise and disruption and the option would cost approximately £5.7bn.

Further options involved MPs and peers partially moving into temporary accommodation, with the programme of work expected to take about 11 years and cost £4.4bn.

A final option involved the building being fully vacated. The report said this option would take the least time and would avoid disruption to Parliament from construction works.

It also said risks to the continuous running of the business of Parliament would be greatly reduced, assuming temporary accommodation could be found. This approach would take around six years and cost about £3.9bn, the report said.

Last night, a Parliament spokeswoman said the option for a newbuild had been ruled out in 2012.

Referring to the cost of the programme at a time of public spending cuts, she said: “The committee is acutely aware that they need to make their decision responsibly and are ever mindful that this is taxpayers' money. This is a key principle they are working to.”

The Palace of Westminster was designed by architects Charles Barry and Augustus Pugin. Construction began in 1840 and lasted for 30 years. It has been a Grade I listed building since 1970 and a Unesco World Heritage Site since 1987.

The National View: Billion-pound Palace repair bill cannot be justified