The Home Office spent £28m on the aborted asylum centre planned for Bicester and "misjudged" the fight against it, watchdogs revealed today.

The National Audit Office said some of the problems with the plans for the proposed centre could have been foreseen - and money saved - if the department had worked in a "more co-ordinated and joined-up way".

Previous reports put the cost of the centre at £25m and last night one of the anti-centre campaigners, Dionne Arrowsmith, condemned the Home Office for spending so much money.

Global Solutions Limited (GSL) was awarded the contract after undercutting another company, UKDS, by nearly £25m to build the 750-bed centre, in 2003 prices excluding VAT.

GSL told the Home Office its total construction cost would be £59.9m, while UKDS bid £84.5 million and a third company, Premier Accommodation Services, bid £69m.

The winning bidder also said it could operate the centre for £15.4m compared with UKDS's £17.9m a year figure, the report revealed.

Such financial detail is usually kept secret by the Government on the grounds of "commercial confidentiality".

After the project was abandoned, the Home Office handed termination payments to GSL totalling £7.9m. The company was also paid £7.6m for design work.

A long-winded effort to win planning permission meant that by April 2005 Home Office officials ruled the project was no longer economically viable.

Capital costs rose and at the same time asylum applications had fallen for a number of reasons, the NAO found.

Chairman of the Commons all-party Public Accounts Committee Edward Leigh said: "The Home Office drove ahead with a project to build a network of asylum accommodation centres, without an eye on what was happening to the numbers of those seeking asylum in the UK.

"And, inexplicably, the department seriously misjudged the level of opposition it would face.

"These factors led to the process being dragged out and the prices getting hiked up."

He added: "The site the Home Office bought is sitting dormant and no-one seems to have any idea what to do with it."

Mrs Arrowsmith, who co-founded the Bicester Action Group in March 2002 to campaign against the asylum centre, said: "I am not surprised the cost has totalled £28m.

"The Home Office had a public enquiry, they employed the most expensive QCs in the country and then had to pay them. They entered in to contacts with various companies and then everybody had to be compensated for the contracts that never were.

"It was a completely ludicrous policy in the first place. It wasn't right for Bicester and it wouldn't be right in any place. The whole scheme was ridiculous - accommodation centres are never going to work wherever they are put."