Ministers announced an “effective ban” on fracking in 2017, however a legal challenge was mounted by Petrochemical firm Ineos.
Following the challenge, a Court of Session ruling in June last year found that as a matter of law, there is no prohibition against fracking in Scotland.
A legal opinion published by Aidan O’Neill QC now suggests that the Scottish Parliament has the legislative competence to pass a fracking ban.
It also indicates that doing so would be less likely to result in successful legal challenges from companies with an interest in the industry.
Friends of the Earth Scotland, who commissioned Mr O’Neill, say that the Scottish Government must now act to definitively ban fracking.
“Communities on the frontline of this dirty industry have been waiting for over four years for the Scottish Government to bring its long drawn out process on unconventional oil and gas to an end,” Friends of the Earth Scotland head of campaigns, Mary Church, said.
“It is time for ministers to live up to their rhetoric and legislate to ban fracking for good.
“Eighteen months ago, the First Minister promised a ban on the industry, but last year the Government’s position was exposed by Ineos’s court case as having no legal force.
“When it is clearly within Holyrood’s power to legislate to protect people’s health, environment and the climate from the fracking industry, continuing only to use policy levers would be a betrayal of the tens of thousands of people across the country who called on the Scottish Government to act to stop this industry.
“Holyrood has a clear mandate from the people of Scotland to do so. If the present Scottish Government cares an ounce about its legacy, then we urge it to work together with the other anti-fracking parties to pass a law banning fracking and finally put this issue to bed once and for all.”
A Scottish Government spokesman said that further assessments would be required before the finalisation of policy on the issue.
He said: “The Scottish Government’s preferred policy position is it does not support onshore unconventional oil and gas development in Scotland.
“Scottish Ministers are entering the final stages of the policy making process on this important issue. The preferred policy position is subject to a statutory Strategic Environmental Assessment and other assessments before a policy can be finalised.
“These assessments, which involve public consultation, are the latest steps in a cautious, evidence-led approach the Scottish Government has adopted in its policy-making process on this issue.
“The Scottish Government does not consider new legislation is necessary to control unconventional oil and gas development in Scotland and the adoption of a strong policy would provide appropriate and proportionate means to regulate such development.
“The practical effect of the current moratorium, and the policy-making process currently under way, is that no fracking or other unconventional oil and gas activity can take place in Scotland at this time.”
Claudia Beamish MSP, Scottish Labour’s spokeswoman for Climate Change and Environment, said: “This is a significant development that adds some much-needed clarity to the fracking debate in Scotland.
“The SNP told the Scottish Parliament in clear terms that it would ban fracking in Scotland, before they awkwardly backtracked on that commitment before Parliament and the court.
“This legal opinion shows Holyrood not only has the powers, but crucially that a ban in primary legislation is the surer way to defeat future legal challenges.
“It is time for the SNP to finally recognise the strength of the Parliament’s will on this issue, and to take a concluding position to ban fracking in Scotland - no ifs, no buts.”