Lord Rogers - whose firm was sacked as the architects behind the scheme because of spiralling costs - said he was still prepared to build the scheme for the original estimate.

Vision: Sir Richard is proud of his design

But he urged the assembly to appoint an independent management team to oversee the project.

"This is classic stuff. Someone is trying to destroy the building and has succeeded," Lord Rogers said in an interview with Thursday's Dragon's Eye programme.

"I think it is down to the horrific incompetence of the management structure."

The eminent peer has insisted he could build the HQ to budget despite a row over spiralling costs.

And Welsh Finance Minister Edwina Hart said she would be prepared to look at his proposals and has offered talks to find a way forward.

The management and civil servants are not up to procuring a building of this quality and to these costs

Lord Rogers

Mrs Hart said: "If Lord Rogers wants to give me detailed proposals in writing that are supported by figures I will certainly have a look at them.

"There is obviously a note of caution because I have sought independent advice on the figures and the building cannot be built on those.

"He is an internationally-respected architect, we would have loved to have worked with him and got the building delivered."

Mrs Hart had announced on Tuesday that Lord Rogers's partnership was being dropped in a row over escalating project costs.

Members voted to suspend work on the new building - four months in to construction - until a new, cheaper tender can be found.

Edwina Hart said it was no embarrassment

Lord Rogers, who was behind the Millennium Dome, the world's largest airport in Madrid and the Pompidou Centre in Paris, said the Assembly HQ was "one of the best buildings we have ever designed".

He added: "We are willing still to guarantee the original price if it is run by a professional, probably a private developer, organisation.

"The management and civil servants are not up to procuring a building of this quality and to these costs."

The assembly's latest estimates show that building the chamber would cost at least �24m, while the complete project would break the �40m mark.

'Cost pressures'

Ministers also said there is now no hope of completing the project before the next Assembly elections in May 2003.

Work on the foundations began four-and-a-half months ago.

The assembly had originally capped the project cost at �26.6m.

In January, the finance minister identified the emergence of "cost pressures".

Mrs Hart's review found the anticipated costs had ballooned drastically.

A party briefing leaked to BBC Wales explained the total project cost had in fact reached between �37m and �47m.

The chamber project is also behind schedule.