THE £5.6 BILLION pound plan to restore Parliament by the 2030s is at risk of going over budget and experiencing delays before it has even started, a watchdog has warned.
The National Audit Office (NAO) has warned that the body in charge of the palace's refit must tighten its scope and become more aware of risks that could send cost spiralling - like the shortage of tradesman with the specialist skills needed to work on heritage sites.
It also says the body must clarify how it will handle late requests to change the plan from MPs and Lords, which could cause costly delays.
Warning that refit of Big Ben saw the budget for construction works rise by 176%, it says the body in charge of restoration will need to keep a tight watch on finances.
The board is due to submit a business case, which will include a budget range and full details of the work involved, to both the Commons and the Lords by 2022.
It is currently estimated to cost £5.6bn modernisation and will not see MPs leave the palace until 2025 at the earliest.
Under the agreed plans, MPs are expected to move to Richmond House, the former home of the Department of Health.
The NAO report flagged that the £4 billion cost previously reported was likely to be a "median" figure, with the final outlay on the Unesco World Heritage Site expected to be higher.
Gareth Davies, head of the NAO, said: "It is vital that, from the outset, the sponsor body and Parliament work together to apply the lessons from other major projects.
"This will allow them to manage the risks to value for money and timely delivery, and maintain public confidence in the programme."
Parliament authorities spent £369 million maintaining the estate between 2015-19 and in the last five years, 29 incidents on the estate could have led to a fire.
Meg Hillier, chairwoman of the Public Accounts Committee, said: "This NAO report shows why the restoration programme must continue without any further delay.
"However, Parliament must make sure that the programme's governance arrangements protect the taxpayer from the delays and cost increases that so often plague major projects."
Sarah Johnson, chief executive of the Parliament's restoration and renewal sponsor board, said her team is committed to ensuring "value for money" during what she called the "most complex heritage project ever undertaken in the UK".
"I welcome the NAO's helpful recommendations as we embark on the task of designing and delivering the plan to protect the Houses of Parliament for future generations," she said.
"We are committed to learning lessons from previous infrastructure projects and will ensure value for money at every stage through stringent audit and assurance processes.
"Our teams will continue to work closely with Parliament in the coming months to determine the requirements for this great building, the home of our democracy."
