Sir Keir Starmer has said the end of oil and gas extraction “has to happen eventually” and the “moment for decisive action is now”.

In a speech laying out his party’s green agenda, the Labour leader called the transition to clean energy “the race of our lifetime” as he sought to reassure industrial communities that his plans would not leave them behind.

Sir Keir said that 50,000 new jobs could be created in Scotland alone, amid a dispute with unions over his pledge to ban new North Sea oil and gas exploration.

“I know the ghosts industrial change unearths,” he told the audience in Leith.

“As a young lawyer, I worked with mining communities to challenge the Tories’ pit closure programme, but deep down we all know this has to happen eventually and that the only question is when.

“So in all candour, the reality is this, the moment for decisive action is now.”

The Labour leader insisted ending new North Sea oil and gas extraction will help communities profit from clean power projects, following concerns about job losses and damage to the local economy.

Bur he warned those opportunities will “pass us by” if the transition is delayed until oil and gas runs out, something he said would be “a historic mistake”.

“We’ve got to seize the new opportunities, this is the race of our lifetime and the prize is real,” Sir Keir said.

“We can cut bills, create jobs and provide energy security for Britain. That’s what a Labour Government will deliver.”

Labour is pledging to take up to £1,400 off household bills and £53bn off energy bills for businesses by 2030.

Central to the plan is the party’s proposed new public body, Great British Energy, which Labour says will collaborate with councils, communities and the private sector to bring down energy costs.

Sir Keir has already pledged to set it up within a year if his party wins the next election and today revealed its headquarters will be based in Scotland.

Further details set out by the party on Monday include a local power plan to allow households across the UK to receive discounts on their bills if their area signs up to new green initiatives.

The body would make available up to £600 million in funding for councils and up to £400 million in low-interest loans each year for communities.

Elsewhere, Labour said that the ban on new onshore wind would also be axed within months of the party entering government, with new measures introduced to ensure relevant regulators have a net-zero mandate.