The contract to run Europe's biggest waste service is now under threat of a legal challenge. Greater Manchester Waste Disposal Authority (GMWDA) confirmed its £3.8bn PFI contract signed with Viridor Laing (Greater Manchester) in April was being challenged in the courts by one of the firms which lost the race for the tender. The 25-year contract is now subject to legal proceedings issued by waste-management firm Sita UK, which also bid for the contract, which alleged GMWDA had ‘breached procurement regulations. The company claimed the authority ‘failed in its obligation to assess the tender so as to identify the most economically-advantageous tender', and was in breach of EU law as a result. Sita UK is seeking unlimited damages. A company spokesman said: ‘Our point is that significant changes occurred to the project since the appointment of the preferred bidder. ‘Sita UK should have been invited to submit a revised bid alongside Viridor Laing's bid.' But GMWDA's finance director, John Bland, rejected the claim. He said: ‘We don't believe we have done anything wrong and maintain that this action is wrongly judged. ‘We are trying to clear up exactly what the issues are. We have gone through all the proper processes and have a full record of transparency.' The firm also announced this week it had submitted an appeal to the Planning Inspectorate against the refusal of planning permission for the Cornwall Energy Recovery Centre (CERC). The appeal is being backed by Cornwall Council which agreed a contract with Sita for the facility which would supply energy to local businesses. David Buckle, project director at Sita UK, said: ‘There is a pressing need for the CERC, which can avoid the looming waste problem, while putting non-recycled rubbish to good use to generate a reliable source of energy. ‘A successful appeal provides the greatest chance of delivering this much-needed facility.'