MPs today said the £4bn-£6bn scheme had moved “a step closer” after a critical review of the project concluded that urgent restoration work is essential.

The review concluded that the 150-year-old building is falling apart faster than it can be fixed, with the cost of maintenance projects and ongoing works recently doubling in just three years to £127m annually in 2018/9.

As previously planned, work is now expected to begin on the Palace of Westminster in the mid-2020s.

The review also confirms the strategy of temporarily locating MPs on Parliament’s northern estate, and Peers in temporary accommodation at the QEII Conference Centre, as the best option.

The report has recommended new ways of phasing the restoration work to minimise the time MPs and Peers would spend in temporary accommodation, including accessing the Palace from the river to carry out work.

Sarah Johnson, chief executive of the Restoration and Renewal Sponsor Body, who ordered the comprehensive review when she accepted the job, said:  “The iconic home of Parliament is in urgent need of restoration.

“The review has found new ways of carrying out the complex project, focused on getting value for money, and we will continue preparing a detailed and costed restoration and renewal plan that will for the first time give Parliament a true sense of the costs and timescales of restoring the Palace of Westminster.”

The restoration team will develop a detailed and costed plan, that will for the first time give Parliamentarians estimated costs and designs for a restored Palace of Westminster.

This work will include more than 100 investigative surveys, with specialist teams spending thousands of hours analysing the building, including the 1100 rooms and more than 3000 windows.

The team will also continue work with Parliament to determine all the functions the building needs to have in future as well as look at vital improvements in areas like accessibility.

The restoration programme will now work with Parliament to work out the best way to accommodate MPs on its northern estate.