Large chunks of Oxford's historic assets may be sold off to pay for improvements to the city council's rundown housing stock.

Oxford City Council has to find about £30m during the next six years to radically improve its houses to meet stricter Government standards.

More than half the 8,000 council houses in the city are sub-standard and fall short of new criteria.

Three years ago, the Liberal Democrats and the Greens, who controlled the council, suggested selling the houses to a private association. The sell-off would have netted £12m and relieved the council of responsibility for maintenance.

Labour scrapped the plan when it took power in 2002.

Tenants are being consulted and the council will make a decision around the middle of next year The city council faces four options:

Arms Length Management. The council retains ownership of housing stock, but employs managers for day-to-day running. Before this can be done the council must improve its repairs service

Sell housing stock to a private association, which is unpopular with the Labour group

Raise funds from the private sector, which is also unpopular with the Labour group

Sell the council's most valuable assets.

John Goddard, group leader of the city council's Liberal Democrats, fears the ruling Labour administration will be pressured into selling the family silver.

"We're talking about having to find £5m every year until 2010," said Mr Goddard.

"Where is that sort of money going to come from? The council daren't load it onto tax. "Basically, there are four options. One of those - known as Arm's Length Management - would be unobtainable because of the council's poor record for house repairs. Two of the options - handing over large blocks of homes to housing associations or raising funds from the private sector - would be anathema to Labour members.

"So we're left with selling off council-owned landmarks. The problem is that you can only flog the family silver once.

"And as soon as you've got rid of something of value, you deprive yourself of the revenue from it in rent. It's the road to ruin."

Labour council leader Alex Hollingsworth admitted that a sale was one of the options, but denied that it was inevitable.

However, "worst case scenarios" were being discussed, he said.

Fifteen derelict lock-up garages have been identified that are beyond repair and could be sold for development, though this would bring in only a small amount.

The jewels in the crown are shops in George Street and Broad Street, which all belong to the council. So, too, are half the properties in High Street and Queen Street.

The council also owns the Westgate Shopping Centre, parks and farmland. Rent from these raises between £6m and £7m a year. Mr Hollingsworth was hopeful that the council's repairs operation could reach two-star rating - the standard needed in order to be eligible for an Arm's Length Management agreement.

County councillor John Power, who represents Oxford West, feared some form of sale would be necessary, but hoped that an auction of leaseholds, rather than disposing of freeholds, could be arranged.

Debbie Dance, of the Oxford Preservation Society, called for a "fullscale public review" before any action was taken.

She said: "It's risky. Short-term gains have to be balanced against the city's long-term good."