Confidential documents have revealed that Oxford would suffer serious economic damage if a hash is made of the Westgate redevelopment.

Plans for the £300m scheme to transform the shopping centre are due to be considered by a specially-convened planning committee later this month.

But papers leaked to the Oxford Mail show real concern at the consequences of the project failing.

A report by city council finance officer John Kulasek raises the spectre of the disastrous Cornmarket Street repaving project - the joint city-county scheme that ended up costing nearly £5m - twice the original estimate.

The Westgate redevelopment is a deal between Oxford City Council and the Westgate Partnership, including Capital Shopping Centres - the company running venues like Lakeside in Thurrock and Cribbs Causeway in Bristol.

The council has been guaranteed a minimum rent of £2.5m a year for the duration of the construction period (estimated at five years) in lieu of car park fees and charges, but it will not have operational control over the rebuilt car park.

The report warns: "The council would be exposed to a financial risk if the development were to adversely affect its annual revenues or capital asset value, reducing the council's ability to provide future services without replacement revenue. Poor construction and design standards of the proposed development, were they to occur, would adversely affect the future economy and environment of Oxford, and adversely affect the council's reputation."

The council has the ability to withdraw from its contract if certain 'show stopping' milestones were to occur, including the scheme failing to get full planning permission or surveys revealing archeological problems.

The report continues: "As the development will take approx- imately five years to complete and would be a scheme of considerable complexity, there are a number of large risks to the council that, if not properly managed, could have a significantly adverse effect."

The 5.1 acre Westgate site is currently worth £8m, but once the development is complete, it would be worth £50m to the city council.

Graham Jones, of pressure group Rescue Oxford, said: "The city council is the landowner and the planning authority, that might be good for their coffers but it might not be good for the city overall - it's a difficult position to be in."

City councillor Sushila Dhall said: "Cornmarket was an example of the kind of thing that can go massively wrong.

"Westgate is a huge amount of land and even if half the things went wrong, it would be a horrendous fiasco."