The Prime Minister has insisted that “we’re going to take every last drop” of oil from the North Sea as he defended the decision to give the largest untapped field the go-ahead for development.

The UK Government’s regulator, the North Sea Transition Authority (NSTA), approved plans by Norwegian energy company Equinor and British firm Ithaca Energy to open up the Rosebank field, near Shetland.

It is thought to contain up to 300 million barrels of oil, but critics – including Scottish First Minister Humza Yousaf – said the development will damage net zero ambitions.

Read more: Analysis: UK Government fails to reap benefits of net zero s Rosebank approved

The vast majority of the fossil fuels in the Rosebank field is oil, meaning it will likely be exported outwith the UK, throwing doubt on the UK Government's claims it will boost energy security.

Suggestions by the Prime Minister that home-grown oil and gas are better for the environment than imports have also been found to be false, with Norwegian pipeline imports less carbon intensive than UK North Sea fuels.

Read more: Revealed: Rishi Sunak's 'false' claim North Sea oil and gas cleaner than imports

In an interview with STV News, the Prime Minister stood by the decision to give the go-ahead for drilling at the Rosebank oil field.

Despite vast criticism from climate scientists, campaigners, political opponents and allies to row back on environmental commitments, Mr Sunak said his government was “absolutely not” wishing away net zero ambitions.

He said the UK Government was “committed” to the targets despite postponing a ban on new petrol and diesel cars by five years, to 2035.

The decision, he said, was taken to ease the cost burdens on ordinary households.

And asked if he thought the UK should take “every last drop” of oil from the North Sea, Mr Sunak said: “I think the UK should focus on the North Sea because we’re going to take every last drop. I mean, we need oil and gas for decades to come.

“So yes, I would much rather have that from home because it’s better for our energy security. It’s better for our economy and it’s better for our jobs now.”

Read more: SNP Energy Minister at odds with Humza Yousaf over oil transition

But pressed again whether that approach means “taking every last drop”, he said: “I think that is absolutely the right thing to do, because that’s better for our country.

“It’s better for jobs, it’s better for our energy security, and by the way, better for carbon emissions.

“When we import gas from somewhere else around the world, it comes here with three or four times the emission that you would get from getting it here at home so yes I do think it’s the right thing to do.

“It’s the right long-term thing to do for our country, and that’s what I’m always going to do.”

Mr Sunak previously insisted his government wanted to “max out” developments in the North Sea as he supported future oil and gas licensing rounds.

Read more: Low-paid workers 'being left behind' in Scotland's net zero move

Following Rosebank’s approval on Wednesday, Mr Yousaf said: “I think Rosebank is the wrong decision. The decision that has been made today it is not the right decision to be made.

“Scotland’s future, the North East’s future, is as the net zero capital not just of Europe but of, I hope, the world.

“And of course, new oil and gas licences being given the go-ahead will slow the pace of that transition down.

“I want to accelerate that transition and take the workers with us.”