A payment row has broken out on a £150m project to create an energy-from-waste plant in Aberdeen.
Main contractor Acciona confirmed it was keeping a close eye on the tense situation on the Ness site in northern Scotland.
A subsidiary of the Spanish construction giant, EfW Ness Ltd, is building and operating the 14MW plant for Aberdeen City Council.
A spokeswoman said: “EfW Ness Ltd is aware that one of its subcontractors, Randridge, is in discussion with some of its own agency workers regarding payment of invoices.
“EfW Ness Ltd is up to date with all payments to subcontractors and is working closely with all parties to minimise operational impact. This dispute does not involve EfW Ness Ltd.
“The health, safety and welfare of all personnel on site is paramount to EfW Ness Ltd, and the situation will be monitored closely.”
When completed, the plant will process up to 150,000 tonnes of waste each year from Aberdeen City, Aberdeenshire and Moray councils. Energy produced from burning the waste will power a district heating network.
Aberdeen City Council and engineering services specialist Randridge, which is headquartered in Ireland and has offices in Aberdeen, have been contacted for comment.
Pay is a high-profile issue this year amid soaring inflation and bills.
Balfour Beatty Vinci last month apologised for late payments to workers on the West Midlands leg of the £100bn High Speed 2 (HS2) scheme.
Meanwhile, trade unions Unite and GMB organised a demonstration in March as part of a campaign to force the Swiss contractor behind a Leeds energy-from-waste plant to pay workers according to the terms of an industry-standard working-rule deal.
Last week, dozens of construction workers gathered in central London to protest about what they called a “derisory” pay offer from the Construction Industry Joint Council.