"The job losses came as a major surprise as there is 18 months' worth of work left to complete on the project," Unite said. "The redundancies have led to fears that the entire site could be mothballed," the union added.
A total of 800 redundancies have been made in the past month "and further job losses are expected", Unite said. The site currently has a "skeleton workforce" of around 350 workers.
The UK government's Low Carbon Contracts Company's contracts for difference (CfD) register shows an expected generation start date of 31 March 2020 for MGT, from its latest update on 1 August. MGT was awarded a 15-year CfD subsidy with an inflation-linked strike price of £125/MWh in 2014.
There were several reported strikes at the construction site earlier this year, but MGT confirmed to Argus on 12 June that construction was back under way.
MGT is the world's largest newbuild dedicated biomass plant. It will consume 1mn t/yr of wood pellets when running at full capacity, all of which will be supplied by US wood pellet producer Enviva.
Construction is managed by Spanish engineering and construction company Tecnicas Reunidas and engineering firm Atlantic Projects Company.
Finnish utility Fortum has signed a 10-year contract to operate and maintain the CHP once construction is complete.