THE costs of building the Turner Centre, Kent’s flagship arts centre, have spiralled to nearly £30 million - around four times the original estimates, it has emerged.

It has also been revealed that the centre, being built alongside the stone pier at Margate, is now expected to open in the first six months of 2008, four years later than first forecast.

And in a further blow, Kent County Council says it is still around £9.8 million short of what it needs to build the distinctive gallery, which will be partly bedded in the sea.

Despite the £4.5 million increase in costs, KCC remained defiantly upbeat about the scheme. Council chiefs insisted their efforts to secure more sponsorship from wealthy private donors will help bridge the gap.

However, they conceded KCC could still be left with a bill for £20 million if those sponsors do not come forward to supplement the £4.1 million that has already been pledged by the Arts Council and a further £4 million from SEEDA - the South East England Development Agency.

However, the news of the spiralling costs and setback in opening is bound to spark concern the centre could prove a financial burden on the council taxpayer.

In a report, KCC says costs rose because a bouyant construction market led to fewer companies bidding for the contract to build the centre, which has been designed by Norwegian architects Snohetta and Spence.

The report, presented to KCC’s Conservative cabinet in September, also says rising steel prices and protracted wrangles over the construction contract with Edmund Nuttall have helped push up costs.

Council chiefs remain bullish about the scheme’s future and its potential economic impact on the town.

Cllr Mike Hill (Con) KCC’s cabinet member for community services, said: "We were in a weaker position because of the sheer amount of work available in the construction market.

"This project has already generated a noticeable impact in the area in terms of property prices and the wider public recognition," he said.

But local Margate county councillor Clive Hart said KCC should rethink the scheme. "I am keen for it to be built because it will help regenerate the area but these spiralling costs are causing concern for many residents.

"Even at this stage, it might prove more feasible to build it on dry land rather than half in the sea."

The vision for the arts centre was first set out in 2001. Named after the landscape master Joseph Mallord William Turner, who spent part of his life in the area, it will feature three galleries.