John Swinney must take a position on new oil and gas drilling, Gillian Mackay has said, as she hit out at the UK Government for approving the Jackdaw gas field.

The Scottish Greens co-leader, speaking during her keynote speech at the party’s conference in Inverness, accused the First Minister of “years of swithering”.

The SNP has moved towards a softer position on oil and gas under Mr Swinney’s leadership following years of opposition to new fields under Nicola Sturgeon.

Mr Swinney has previously said any new oil and gas field should pass a “climate compatibility test”, rather than stating his support or opposition.

He said the UK Government’s decision to approve Jackdaw would provide “certainty” to workers.

With the decision on the much bigger Rosebank still to be announced, Ms Mackay urged the SNP leader to oppose it.

She said: “After years of swithering (the SNP) seem to be happy with Jackdaw too, or maybe not – they don’t seem to have made up their minds.

“They’ve welcomed the ‘certainty’ of Burnham’s decision but don’t seem to be able to find any certainty about whether they agree with it or not.

“Labour in Westminster and the SNP in Holyrood – both of them seem unable to take the climate crisis seriously, they don’t seem able to make the just transition into a reality.”

With energy reserved to Westminster, Ms Mackay urged Prime Minister Andy Burnham not to let the “disastrous” Rosebank project, the biggest untapped field in the North Sea, go ahead.

“But the SNP need to decide what they think about Rosebank too,” she said.

“They can’t keep hiding behind Westminster – what do they really think?

“John Swinney needs to decide as a matter of urgency where the SNP is going on oil and gas and the climate emergency.

“Are they going back to being the pro-oil party of the past? The first person to welcome Jackdaw was Donald Trump – do they really want to fall in line behind that tangerine eejit?

“Are they going to turn their back on Nicola Sturgeon’s legacy, of a more responsible approach to oil and gas that followed the climate science?

“The SNP can double down on fossil fuels.

“Or they can protect our future generations from climate breakdown. But they can’t do both.

“First Minister, we know where we stand but what about you?

“It’s time to put people and planet before the profits of money-hungry corporations, like Shell, Equinor and BP.

“First Minister, do you have the courage to oppose Rosebank?”

The Scottish Government has been approached for comment.