Officials are trying to plug a funding gap of “£200-300m” to refurbish the Aylesbury estate in south London.

Building understands that if the money required to carry out structural works to prevent a “progressive collapse” of blocks – similar to that at Ronan Point in 1968 – cannot be found then the project is likely to be abandoned and the towers demolished.

The cash crisis emerged this week as it was revealed that Levitt Bernstein, the architect involved in the first phase of the refurbishment in the south-west corner of the estate, was compiling a report to clarify its role. This will cover every stage of the suspended £32m project. Southwark council will meet in September to decide what to do.

A source close to the scheme said: “Right now we are all just waiting. The council will have to think hard if it is going to salvage the situation. It seems the only realistic option is demolition.”

Referring to a proposal, rejected by tenants, to transfer the homes to a housing association in December 2001, the source added: “The council cannot abandon a project again. The residents are still suffering and there is still the decent homes target to implement [by 2010].”

A spokesperson for Aylesbury New Deal for Communities, which is providing £56m in public funds for the project, said: “The project has been suspended since March because of the potential collapse of some blocks built using the ‘large panel system’. As a result the council will have to find additional funding. We are looking at £200m-300m.

“The decision that has to be made is whether or not to go ahead with the current proposals. There is a chance that the whole thing could be scrapped.”

Officials had hoped that the £32m Levitt Bernstein plan could begin this summer after it announced last September that it had secured the final £7m required. The plan was the fifth in eight years that had been drawn up for the estate.

Right now we are all just waiting. It seems the only realistic option is demolition

Source close to the scheme

However, it emerged in January that Southwark council was conducting an urgent inquiry into the danger of a “Ronan Point-style” collapse.

The findings of this report, by Alan Conisbee & Associates, showed that 700 homes were at risk from a collapse caused by a gas explosion.

It recommended that gas supplies should be removed as a “high priority”. This work is proceeding.

Levitt Bernstein declined to comment.

n Southwark council has issued further bidding details to the seven shortlisted developers for the £1.5bn regeneration of Elephant and Castle in south London. The documents outline the council's preferred options for the development of the transport and access. These include a network of open spaces, opening up railway arches to be used as a thoroughfare and straightening the main road.

The seven bidders are: Key Property Investments, Lend Lease, Oceancrest, Canary Wharf Group, Prudential Property Investments, Multiplex and Taylor Woodrow. Responses are due by mid-autumn and a final bidder will be appointed in early 2006.