Kezia Dugdale has said Scottish Labour will change its position and oppose fracking.

The party's leader made the comments at Holyrood during First Minister's Questions on Thursday during which Nicola Sturgeon said insisted fracking in Scotland "ain't allowed to happen".

Ms Dugdale demanded to know if SNP opposition to the unconventional extraction of oil and gas is "a real promise" or "just an election pledge".

She said Ineos owner Jim Ratcliffe had been given "private assurances" by the SNP that it is not opposed to the controversial process, despite the Scottish Government having announced a moratorium on fracking last January.

Ms Dugdale said the petrochemicals boss claimed to have had "private assurances from her government that the SNP aren't against fracking", adding :"His quote says 'they are being quite clear, what they have said to us is they are not against fracking'."

She demanded: "What does he know that we don't?"

The Labour leader also said the Scottish Government's environment agency had tendered for research into decommissioning on fracking, asking Ms Sturgeon: "If she isn't planning to frack, why is she preparing for the clean-up?

"Is the SNP promise to stop fracking a real promise or is it just an election pledge?"

Ms Sturgeon said: "I know Labour are desperate - and I know why they are desperate - but this really does take the biscuit.

"Just for the avoidance of doubt, there is a moratorium on fracking in Scotland, it is clear and simple, there is a moratorium on fracking, that means no fracking."

She insisted the Scottish Government's position is "clear", telling MSPs: "We will not allow fracking. We will not allow fracking in Scotland because we will not take risks with our environment while there are still unanswered questions, that's why we've got a moratorium in place.

"There will be no fracking in Scotland because there is a moratorium on fracking, that is what a moratorium means, it ain't allowed to happen because we won't take risks with our environment while there are so many unanswered questions. That is the responsible way of proceeding."

Responding to Ms Dugdale's comments, Patrick Harvie, economy and energy spokesman for the Scottish Greens, said: "Scottish Greens led Holyrood’s first debate on fracking, calling for a ban, in May 2014.

"MSPs from all parties voted against it. Labour’s sudden conversion a few weeks before an election is late but welcome.

"Pressure from the Scottish Greens led first to a moratorium on fracking, then extended it to other dangerous methods of unconventional gas extraction. We remain determined to keep up the pressure for a full, permanent ban."

Friends of the Earth Scotland head of campaigns Mary Church said: "It is fantastic news that Labour have come out unequivocally opposed to fracking.

"A huge amount of evidence about public health, environmental and climate impacts from around the world provides a strong precautionary basis for banning this unsafe and unnecessary industry, and the Labour Party in Scotland have recognised that."