AN SNP campaign group has hit out at their party leadership after a grassroots bid to push for a fracking ban in Scotland was blocked.

More than a dozen SNP branches had backed a motion ahead of the party's Spring conference that would have asked delegates to support a ban on unconventional oil and gas extraction.

However, a powerful party committee blocked the motion from being discussed despite the significant support from members.

SNP Members Against Unconventional Oil and Gas, known as SMAUG, issued a statement in which it said it was "deeply disappointed" with the decision not to approve a debate.

Had the motion been selected and backed by members, the party leadership would have come under intense pressure to go further than its current position of putting moratoriums in place on fracking and underground coal gasification.

A spokesman said: "This debate could have helped ensure that Scotland was no longer under threat from the damage and pollution caused by highly dangerous techniques such as fracking and underground coal gasification.

"They have ignored the voice of nearly 20 SNP branches, representing thousands of members, who joined together to support a resolution from Edinburgh Eastern calling for this debate. We would like to thank the grassroots SNP members for all their hard work in organising discussions and votes on this matter, and for their continued support. We would like to assure them, the fight will continue."

The Scottish Government has said that it will be led by evidence on the question of whether to allow fracking, with a decision expected to be taken in 2017 at the earliest.

Some SNP members fear that the continued prevarication will see the party lose support to the Greens, which back a total ban, while some party activists have been stung by attacks from other pro-independence parties over the ambiguous stance on the issue.

A spokesman for the SNP said that fracking had been discussed at the party's conference in October and that it therefore was not necessary to revisit the topic.