BOSSES behind a £250m energy Teesside plant have refused to bow to union demands over a pay wrangle.

Sita Sembcorp UK (SSUK) has snubbed calls for a wage audit, amid union claims foreign construction workers are being underpaid at its factory in Wilton, near Redcar.

Unions have long alleged undercutting at the waste-to-energy site, with hundreds of protesters demonstrating near the plant over pay, poor treatment of migrant staff, and a disregard for safety.

Last week, CNIM Clugston Wilton, which is overseeing construction, ripped up two sub-contractors’ agreements after an investigation into salaries, though officials said more than 60 were offering incomes above national agreements.

SSUK’s latest rebuttal comes after wage talks between the company, unions and the Merseyside Recycling and Waste Authority (MRWA), which previously awarded SSUK a deal to turn waste into energy.

Unions, including Unite, GMB and Ucatt, want an independent review into pay packets, but Ian Sexton, SSUK chairman, said there is nothing wrong with its salary structure.

He said: “The meeting was independently chaired by the Advisory, Conciliation and Arbitration Service (ACAS), and, in the spirit of openness, we accepted a demand from unions that two individuals leading the demonstrations attend.

“We explained, having thoroughly investigated all allegations made by unions, including carrying out an extensive wage audit, that there is no evidence of any systematic underpayment of foreign workers.

“We presented the detailed results of the audit to MRWA and offered to submit the same detail for independent verification by ACAS, so trade unions could be satisfied there is no underpayment of foreign workers.

“The unions called for a full forensic audit, which would include handing over employees’ bank details and other confidential personal information, but we don’t think this is a reasonable request.

“We will continue to work with all parties to seek an end to this protest.”

The plant is due to open next year, and is expected to convert more than 400,000 tonnes of household waste from Merseyside into electricity and steam.

It will create about 50 permanent jobs when work starts.