JOHN Swinney has been accused of preparing to give fracking the green light north of the Border as he wants taxes from the controversial gas process devolved to Holyrood.

The Deputy First Minister called for changes to the Scotland Bill, now going through Westminster, that would hand Holyrood powers to impose charges on drilling companies.

He told MSPs the move was "purely for policy completeness" but faced claims her was paving the way for the Scottish Government to cash in from fracking, also known as unconventional gas extraction.

The Scottish Government ordered an indefinite moratorium on fracking in January, amid growing public concern at the environmental impact of the process in which water and chemicals are pumped underground at high pressure to fracture the rocks and release gas.

It is preparing a major safety study and has promised a public consultation before a decision is taken on whether to consider commercial projects.

However, ministers have refused to say whether companies have been banned from exploratory drilling and other preparatory work under the terms of the moratorium.

Energy giant Ineos, based in Grangemouth, Stirlingshire, which has licences to frack across 700 square miles of the central belt, has embarked on a major public relations drive to reassure the public since the firm's billionaire boss Jim Ratcliffe met First Minister Nicola Sturgeon on the day the moratorium was announced.

Appearing before Holyrood's devolution committee, Mr Swinney called for fees imposed on companies when they secure a licence to be devolved.

The fees, known as "land rental charges" are the equivalent of the "royalties" paid by offshore oil companies and are presently set by the UK Department of Energy and Climate Change.

The SNP has drafted an amendments and is expected to force a vote on it when MPs next debate the legislation.

Mr Swinney was challenged on the plan by Scottish Labour's energy spokesman Lewis Macdonald. He denied the move signalled a desire to allow fracking.

He said: "It is purely for policy completeness. If the power is devolved it should be done properly.

"We believe if the policy function is being devolved it should be devolved completely, not in a half-hearted fashion."

He added: "The government's position on fracking is quite clear.

"There is a moratorium in place and evidence-based research is being undertaken on this question to ensure the public debate is well informed."

Mr Macdonald said later: "The SNP is sending mixed messages regarding its position on onshore fracking.

"Fergus Ewing announced plans for a moratorium on onshore unconventional gas projects at the start of the year, yet today we have John Swinney seeking powers to raise revenues on onshore fracking in Scotland.

"This would be irrelevant if the Scottish Government intended to prevent onshore fracking, and we have to question whether John Swinney's position means that Ministers have already made up their minds to allow it.

"My sense from what John Swinney said today is they are looking for a tax stream.

"The Scottish Government wants to exploit the tax stream from fracking."

He added: "The SNP are saying one thing and doing another when it comes to onshore fracking.

"John Swinney's position at today's committee suggests the so-called moratorium is a short-term fix, and that the SNP are already calculating what money is to be made from onshore fracking in Scotland."

During the General Election campaign the SNP produced official green badges featuring the party logo and the slogan "Frack Off."

The slogan is widely used by campaigners demanding an outright ban on unconventional oil and gas extraction and gave the impression the SNP was opposed to fracking.