The GMB Union has posed questions to Labour on its UK energy policy, including the message for thousands of offshore workers in Aberdeen and north-east England who would be impacted.
Labour leader Sir Keir Starmer will give a keynote speech on Tuesday as Labour moots a plan to see the UK stop using fossil fuels by 2030 for electricity demand.
The party said an emergency backup of 0.7% of fossil fuel production would be kept on standby
For comparison, the past year has seen fossil fuels account for an average of 44.5% of UK electricity generation, according to the National Grid.
Sir Keir said his plans would see the UK to become a renewable energy “superpower”, with a quadrupling of offshore wind capacity, and a tripling of solar.
In response, GMB pointed to the job implications for offshore workers.
It asked: “We built a global centre for offshore oil and gas in Aberdeen, where is your global centre for renewables going to be situated?
“Are you opposing new licences for drilling in the North Sea and if so, what’s your message to thousands of workers in Aberdeen and the North East of England who work offshore?”
The union also asked, “what percentage of the wind farms and solar panels will be manufactured in the UK?” in reference to the number of Britain’s offshore wind developments which have been manufactured overseas.
General secretary Gary Smith said: “It’s all well and good talking about the shift to green industries, but where’s the plan for the tens of thousands of energy workers who will be affected?
“So far, the supposed jobs bonanza in renewables manufacturing has been a sick joke at the expense of UK workers, with authoritarian regimes across the world hoovering up contracts that should be completed here at home.
“We need a plan that understands the value that energy workers bring to their communities and our country.”
Labour has pledged to stop new long-term exploration in the North Sea, and sought an expansion of the UK windfall tax on operators to help households with the cost of living crisis.
On a fossil fuel-free electricity system, Sir Keir told the BBC the goal was “difficult” but “absolutely doable”.
It comes as new Prime Minister Liz Truss has announced she will push ahead with further oil and gas extraction in a bid to make the UK a net energy exporter by 2040.