MINISTERS have been accused of paying lip service to a moratorium on controversial new energy extraction techniques after a firm that wants to ignite coal reserves under the Firth of Forth said it expects to get the go-ahead within months.

Cluff Natural Resources wants to convert millions of tonnes of coal under the sea bed to gas under a process known as underground coal gasification (UCG), a method that the company insists will be managed safely and bring substantial benefits for energy supplies and the economy but has been branded "frightening and experimental" by Friends of the Earth.

SNP ministers have admitted for the first time that they have the power to block the development, as the firm said it planned to submit a planning application in either the Falkirk or Fife council area early next year.

However, the Scottish Government has given no indication that it plans to step in, despite calling a moratorium that SNP energy minister Fergus Ewing said applied to "granting of planning consents for all unconventional oil and gas developments." Mr Ewing initially suggested he had no powers over UCG as it was technically offshore, meaning it was controlled and licensed by Westminster.

But Alex Neil, the Cabinet Secretary with responsibility for planning, said in response to a parliamentary question that Scottish ministers would have the power to determine any planning application for onshore infrastructure related to UCG projects, effectively handing Edinburgh a veto as land-based plants are essential.

The admission has ramped up pressure on the Scottish Government to extend the moratorium to the Firth of Forth project, with more than 1,000 people believed to have emailed Mr Ewing in recent months calling for the move.

Lewis Macdonald, Labour's energy spokesman, said he had written to Nicola Sturgeon, calling on the First Minister to clarify what is covered by the moratorium and confirm that it applies to onshore aspects of UCG developments.

He said: "Alex Neil’s answer to my recent parliamentary question on planning decisions on the onshore aspects of UCG is clear. Ultimately Scottish Ministers can operate a presumption against any such project in the planning system should they wish to do so.

"SNP Ministers have been dodging the important questions on the unconventional oil and gas moratorium for months... The First Minister needs to be clear about the impact of the moratorium. Otherwise the conclusion has to be drawn that the SNP has never had any intention of halting unconventional oil and gas in Scotland."

The call comes as the SNP faces growing pressure to spell out exactly what its moratorium means and accusations that the move was a political calculation for deployment in the general election campaign, in which the party adopted anti-fracking slogans, rather than motivated by any genuine concern over unconventional oil and gas.

Six months on, ministers have refused to answer questions over who will carry out new research or when a public consultation, promised when the move was announced, will take place. Jim Ratcliffe, the Ineos chief executive who wants to establish a fracking industry in central Scotland, revealed last week that the SNP Government had privately assured him it was "not against" fracking.

Correspondence obtained by campaign group Frack Off Scotland through Freedom of Information laws show that Mr Neil personally assured Algy Cluff, the North Sea oil tycoon behind Cluff Natural Resources, that his plans would not be affected by the moratorium shortly after it was announced.

Mr Cluff has also lobbied Alex Salmond and Mr Ewing over his proposals, claiming UCG in the Forth could power a new gas power station on the Longannet site, with the existing coal-fired plant likely to close next March.

Andrew Nunn, the chief operating officer of Cluff Natural Resources, backed the Scottish Government's 'evidence based' stance and said studies already existed that showed UCG could be conducted safely.

"As long as we can demonstrate what we are proposing is in line with previous studies, and can mitigate the impacts, I don’t see any reason why [a planning application] shouldn’t go through quite smoothly," he said.

"We’ve held a number of community engagement sessions that went very well. People are most concerned with about things like traffic, dust and light. They realise this is a tightly regulated area."

Mr Nunn added that coal resources at Kincardine, around 10 miles west of Dunfermline, could be utilised over two to three decades while other reserves could be exploited over half a century. The firm believes gas it extracts will be a valuable resource for the nearby Grangemouth petrochemical plant, and would generate a significant tax windfall for Government.

Dr Richard Dixon, director of Friends of the Earth Scotland, described UCG as the most risky form of unconventional gas extraction and called on the Scottish Government to extend the moratorium.

He added: "Shale gas and coal bed methane were stopped by ministers telling councils and SEPA not to let them proceed. While the licensing for underground coal gasification is different it could be stopped just as effectively by the same route. The lack of a legal definition of unconventional gas has let the SNP give the impression that they have put a stop to it when UCG has so far escaped."

A Scottish Government spokesman said: "The Scottish Government is clear that the development of new energy technologies, such as underground coal gasification, must be consistent with our environmental objectives and we will continue to take a careful, evidence-based approach to such developments."