SNP ministers have been accused of an “erratic and nonsensical” approach to fracking after extending a key licence despite previously claiming to have banned the process in Scotland.

The Scottish Government decided to extend the licence – which is jointly owned by Ineos and Reach Oil and Gas and covers an area of 400km2 to the south west of Falkirk – until June 2019.

But critics said the move added to the "confusion" surrounding the SNP's position, with Scottish Labour branding it a "shambles".

It comes after Scotland’s highest court ruled fracking has not been banned in Scotland, despite numerous “mistaken” statements by SNP ministers to the contrary.

Mary Church, Friends of the Earth Scotland's head of campaigns, said the decision to extend the licence was "disappointing".

She said: "Extending this licence risks adding to the confusion caused by Ineos's recent legal challenge and only increases the pressure on the Scottish Government to move forward with its decision-making process, legislate to ban fracking and draw a line under this issue for good.

"The operators have already had one extension to this licence and despite having consents in place before the moratorium on fracking, they hadn't fulfilled their drilling commitments, so clearly this licence should have been revoked.

"While it is unlikely that the operators will be able to do much in terms of advancing their shale gas ambitions in 12 months, it is an uncomfortable position for the Scottish Government to take given its opposition to fracking."

Labour's environment spokeswoman Claudia Beamish called for an urgent review of the decision, adding: "This is a deeply concerning development.”

She said: "The SNP's position on fracking has been exposed as a complete shambles – firstly claiming it was banned before having to quickly backtrack in the courts.

"Now we learn ministers are extending the licence for extensive fracking in the central belt while finalising business and environmental assessments.”

Liberal Democrat MSP Alex Cole-Hamilton said the Scottish Government's position was "erratic and nonsensical".

But SNP energy minister Paul Wheelhouse said the extension “does not alter the current position”, insisting no council can grant planning permission for fracking.

He added: “The practical effect of the moratorium established in 2015 is that no fracking can take place in Scotland at this time.”