THE cost of repairs to the city's Eastcroft incinerator has risen again – this time by £1.5m.

Last year, Nottingham City Council approved spending £12m on maintenance of the waste-burning plant through to 2010. Even that was £3m more than the council's original estimate.

Coun Katrina Bull, portfolio holder for the environment, said the latest increase could not have been foreseen.

The works are required to improve boilers and grates. The aging incinerator has breached emissions targets on 30 occasions in the last four years.

Coun Bull said the latest improvements would deliver an efficient plant at a much lower costs than buying a new one.

Opposition politicians were unimpressed.

Coun Andrew Price, leader of the Conservative Group on the city council, said: "Here we go again. A project that started at £8m has now gone up by 50%. This is about project management and the inability to get an estimate that is reliable."

Coun Price highlighted other overspending capital projects, such as the redevelopment of Old Market Square and the construction of the new art gallery, Nottingham Contemporary.

"Every time they make an estimate it is a distant cousin to reality."

The plant is run by the Waste Recycling Group under contract to the city and county councils.

The contract governing the operation of the incinerator was signed more than 30 years ago.

Coun Gary Long, leader of the liberal Democrat group , said: "The contract is very poor. The council appears to have no option but to pay this increased amount."

The authority announced last week it had to axe more than 350 jobs to balance its budget for the coming year.

The incinerator supplies 4,500 homes and 150 local businesses with energy.

The city council has estimated it will pay out an additional £2m buying in gas to maintain an energy supply to customers during the period the works take place. It will borrow the money for the repairs.