The architect carrying out the bulk of the work on the first phase of the stricken Battersea Power station redevelopment has attacked the project’s bankers for threatening the entire development.

Ian Simpson Architects was appointed in February to work on the £250 million first phase, which includes 80,000sq m of student accommodation.

A second architect, DRMM, was asked to work up plans for a much smaller part of the first phase, a 200-bedroom private housing block.

But last week the owner of the grade II listed south London site, Real Estate Opportunities (REO), said its bankers were looking at putting the scheme into administration after losing patience with the Irish developer’s attempts to find a partner to bankroll the £5.5 billion Rafael Viñoly masterplan.

Lloyds and Irish National Asset Management Agency (Nama) are carrying a £325 million debt on the project and have given REO until next week to come up with the money.

Ian Simpson said that his firm had finished preparing its part of the work for planning at the end of summer but admitted: “This news has come out of the blue. Our bit was always going to go on hold once we’d completed it but it’s very unfortunate the banks are behaving this way.”

He added: “I’m just waiting to see what happens and how things pan out. A year’s worth of work is being put in jeopardy when the banks know Treasury Holdings has been trying to get an agreement with a third party to take it forward.”

REO is majority owned by Treasury Holdings. Its managing director Rob Tincknell declined to comment on the fresh crisis engulfing the station which has been derelict since 1983.

Earlier this year Tincknell had hailed the appointment of Ian Simpson and DRMM as guaranteeing “a real exemplar of work and place-making” but this week he told BD: “I’m not going to make any comment because of the sensitivity of it all.”

Viñoly was appointed in 2007 to overhaul Giles Gilbert Scott’s long-neglected landmark with a mixed-use scheme that was approved by London mayor Boris Johnson last year and rubber-stamped by communities secretary Eric Pickles in February.

DRMM declined to comment.