More than 400 workers at the Grangemouth oil refinery have received letters saying they are to lose their jobs.
Petroineos is turning the refinery into a fuel import terminal.
The job losses will take effect in a time span from three to 18 months.
Trade union Unite say it's a "national disgrace".
Unite general secretary Sharon Graham said: “It is a quite frankly a national disgrace that Petroineos has been allowed to press ahead with this needless act of industrial vandalism. There is a clear plan for the future of Grangemouth in place. Yet the UK and Scottish governments are missing in action.
Just last week the UK government announced the expansion of Heathrow and said that sustainable air fuel (SAF) will be needed. Well Grangemouth can produce SAF - where is the joined up thinking? It is clear the company is acting in the national interest in China. Who is acting in Britain's interest - who has got Britain's back?
“This the moment for the government to lead and stand up to Petroinoes in the national interest. Petroinoes must allow the transition to SAF and biofuels. If the company refuses the government should be the investor of first resort. There will be 3,500 per cent increase in SAF demand. The market is there.
“Today's announcement will not deter us. We will fight for the future of the refinery and the associated jobs.''
Inquiry into Falkirk death
Falkirk council tax to rise by 15.6%
Changes to Stirling bin collections
Stirling visitor levy consultation launched
Petition against Falkirk service cut