It was due to open last autumn, but the deadline for completion has been put back four times. Council executives say it is unlikely that it will be handed over next month as promised.
A council spokesperson confirmed: "At present, the council is in talks with Mowlem over the matter of delays, but these discussions have yet to reach a conclusion."
Liberal Democrat council leader Paul Crossley says the delays have cost taxpayers £15,000 a week. He wants to try to recoup this money from the contractor.
He said: "The Liberal Democrats have supported the spa project since its inception in 1996. But we have been promised four delivery dates, which have all passed."