GB Energy will be headquartered in Aberdeen, Sir Keir Starmer has said.

Sir Keir and Labour had promised in the lead-up to the election that GB Energy – which he has described as an “investment vehicle” – would have its headquarters north of the border, sparking speculation and repeated questions over where it would be located.

In his first speech to the Labour Party conference since entering Downing Street in July, the Prime Minister said the agency “could only ever be based in one place in Scotland”.

Addressing delegates in Liverpool on Tuesday, he said: “We said, GB Energy, our publicly-owned national champion, the vehicle that will drive forward our mission on clean energy, we said it belonged in Scotland, and it does.

“But the truth is, it could only really ever be based in one place in Scotland.

“So today, I can confirm that the future of British energy will be powered as it has been for decades, by the talent and skills of the working people in the Granite City, with GB Energy based in Aberdeen.”

In a statement released after the speech, Juergen Maier CBE, the chair of GB Energy, said the headquarters will act as a “starting point” for the newly-formed firm.

“We will use this base to rapidly scale up this publicly owned, operationally independent company and start to engage with investors and communities and build supply chains across the UK,” he added.

Within minutes, the Aberdeen and Grampian Chamber of Commerce, which had been campaigning for the agency to come to the region, hailed the “fantastic news” which it said will “secure the north-east’s status as a global energy capital for many decades to come”.

Its chief executive Russell Borthwick added: “With the people, skills, strategic infrastructure and future pipeline of projects already in place, the north-east of Scotland is ready to lead the way.

“However, we do not need to kill off one industry to grow another – in fact, the opposite is true, as one cannot exist without the other.

“We therefore urge the UK Government to use next month’s Budget to restore confidence in the North Sea to protect the jobs, supply chain and energy production we need to ensure a just transition.”

Scotland’s Acting Energy Secretary Gillian Martin welcomed the announcement, but urged the UK Government to “accelerate the establishment” of GB Energy.

“We will now press the UK Government to make sure that this announcement brings real decision making to Aberdeen and adds value to the great work already taking place in the energy transition,” she said.

“More widely, we are working closely with the UK Government as it establishes the GBE team and we would encourage them to accelerate the establishment of the new organisation so that investment in projects in Scotland can be taken forward without delay.”

Stuart Payne, chief executive of the North Sea Transition Authority (NSTA), said he was “absolutely delighted” with the news, adding: “The city was at the absolute heart of the UK’s energy story for the last 60 years, and can do the same for the next 60 – the energy transition will be accelerated and enabled by a world-class workforce, a passion for tackling the hardest technical challenges and a very warm welcome awaits our new colleagues.”

The co-leaders of Aberdeen City Council also said they were “delighted” with the announcement.

“As the energy capital of Europe, Aberdeen is best placed in Scotland to be home to the UK Government’s GB Energy headquarters,” Ian Yuill and Christian Allard said in a joint statement.

“This will help secure future investments in the sector and will help confirm Aberdeen as the net zero capital of Europe.”

SNP Westminster leader and Aberdeen South MP Stephen Flynn urged the Prime Minister to “get down to the business of explaining how GB Energy will bring down energy bills”.

He added: “After all, the legislation itself is barely four pages long, offers no insight into how the body will be structured nor what its strategic aims will be, and doesn’t even begin to outline how energy bills will reduce as promised.”

Scottish Conservative energy spokesman Douglas Lumsden – a former co-leader of Aberdeen City Council – said the announcement will do “almost nothing” to compensate for the “hammer-blow” of Labour policies on oil and gas, after the Prime Minister ruled out approving new licences in the North Sea.

Sir Ian Wood, a well known oil and gas billionaire and chairman of Aberdeen’s Energy Transition Zone (ETZ), urged the sector to work with ministers to shape the agency.

“It is now essential that industry works closely with the UK Government to design GB Energy, ensuring it fulfils its stated ambition as an investment vehicle that accelerates the country’s diversification to green energies.

“ETZ Ltd have a proven track record of working positively with this region’s supply chain as well as developers of the vast array of transformational renewable projects on our doorstep – we stand ready to play our part in making GB Energy a success.”