TUC Congress narrowly backed a motion calling for no government bans on new licences for North Sea drilling on Monday.
Delegates said a fully funded workers’ plan, guaranteeing commensurate jobs for all North Sea workers, must be agreed first.
The union federation also resolved to back the building of Sizewell C nuclear plant and supporting small modular reactors.
It will call for an industrial strategy policy “that maximises our domestic energy strengths for national security, with all assets and options part of the solution: nuclear, renewables and oil and gas production.”
Moving the motion, Unite executive council member Cliff Bowen said: “We demand a real industrial strategy built on expertise and experience of oil and gas workers.
“This is the greatest challenge in energy in our lifetimes. We can show the world what a just transition looks like.”
Mr Bowen was seconded by GMB’s Martina Vrajtoru, Aegis’s Brian Linn and Nautilus International’s Martyn Gray, but opposed by delegates from Unison, University and College Union and National Education Union.
After they warned of the devastating impact of climate change on working people in Britain and across the world, Mr Bowen replied: “They are reversing in New Zealand the exact policy we are about to enact — do not let oil and gas workers become the miners of this generation.”
“Do not be asking us to be giving up our jobs for jobs that don’t exist.”
The government has adopted a target to stop drilling in the North Sea “before any plan for jobs has been agreed,” the motion said.
A card vote was called, with delegates representing 2,712,000 in favour and 2,457,000 against.