Work on restoring and redeveloping historic Eastbrook Hall will not now be complete until July next year, it was revealed today.

Work on the building in Leeds Road, Bradford - once renowned as the biggest Methodist Hall in the North of England - stalled again last month when the main contractor, Ham Construction, went into administration.

About 25 of Ham's employees have been made redundant and the company has ceased operating, according to administrators.

The firm's collapse has delayed work on the restoration of the fine stonework on the facade of the building because the specialists brought in to dismantle and reconstruct it were contracted to Ham rather than to the developers, Aldersgate Estates.

Now Stone Edge, the stonemasonry experts working on the unstable Grade II listed facade, are having to negotiate a new arrangement with Aldersgate.

Richard Denneny, director of Stone Edge, said: "What's gone on is unbelievable. It has been an absolute joke."

He claims his firm is still owed money by Ham for work it has already carried out which he believes was due to the fact that Ham was in dispute with Aldersgate over payments to the firm.

"We are aiming to start again before Christmas providing we can get the paperwork and contractual stuff in place," said Mr Denneny.

"The facade is 75 per cent complete and we were going great guns. If we could have carried on, the facade would have been finished by now. We have got more than £20,000 of carved stone sitting on the ground in a storage lock-up that we are not getting paid for. It's frustrating."

Alan McMahon, director of London-based Aldersgate Estates, said: "Ham have not gone down because of Eastbrook Hall. It's not that we have underpaid them. If anything, we have overpaid them."

He said Aldersgate could have claimed a further £300,000 from Ham.

Mr McMahon said: "We won't take suggestions that we underpaid them and that we are responsible for their insolvency. They have got other projects that they have had trouble with. The delays have been so frustrating to us but we are now confident we are back in the driving seat."

Mr McMahon said the scheme could now be completed by July 2008. At one stage, it was hoped that the restoration of the facade and creation of 73 apartments could be completed by summer 2007.

Joe McLean, a partner at Ham's administrators Grant Thornton, said: "The company had a couple of key contracts, some of which were coming quite near to the end. On one of those large schemes, the partner chose not to let Ham bring it to conclusion because they were in administration and, as a result of that, we have had to make the team redundant.

"The workforce that numbered about 25 to 27 people were made redundant and there are about four or five office staff helping with the administration.

"I am in discussions with various parties who have got obligations to Ham."