Confusion over specification means M&E work is unfinished on eve of £250m building’s completion.

Further problems have emerged at Portcullis House just before its handover to MPs on Monday.

It is understood that a number of offices in the £250m parliamentary building have been rejected because of trouble over the installation of electrical sockets. An insider said skirting in all but a few of the MPs’ offices on a number of floors has had to be removed to fit new sockets.

The source said the original specification for the sockets had changed but that this information had not been passed down the subcontract chain. He said: “It’s a cock-up and someone is going to end up paying a lot of money to sort it out. It’s growing into a big problem.”

It is understood that up to two lengths of the skirting in each office have had to be taken out and reinstalled over the last few days as electricians worked on the problem.

“It could delay things, but who pays for all this extra work and who is ultimately responsible is the big question,” the source said.

It’s a cock-up and someone is going to end up paying a lot of money to sort it out

Portcullis House Insider

M&E contractor Kvaerner Rashleigh Weatherfoil carried out electrical work on this part of the building. A spokesperson for Kvaerner said: “We are unaware of any problem with the building. We are happy to look at any issues that come through to us.”

Laing, the main contractor for the scheme, declined to comment.

The Parliamentary Works Directorate, which is responsible for the construction work on Portcullis House, was unavailable for comment.

Another insider said skirting in a number of offices had been removed and reinstalled as many as three times because of the problem. “Some of the electrical work was subbed out and the specification for the socket boxes was wrong. Workers are taking skirting off in lots of offices.”

The insider added that, while the handover could still go ahead on Monday, the work was unlikely to be completed before then.