Deep mining requires significant investment to get under way

First Minister Alex Salmond recently said the industry could have a "vital role" in the nation's energy needs.

It has prompted speculation that Canonbie could be a development target due to large underground reserves.

However, a spokesman for Scottish Coal said it would need long-term political commitment for the plans to progress.

He said all that had been done so far was to study old records of where coal could be mined.

The company are keen to support open-cast and deep mining - the problem is the economics and the politics Scottish Coal spokesman

"They have looked at the old records from the Coal Board days," the spokesman said.

"They had quite extensive records of what they thought was left.

"They still think there is a lot of coal out there."

The spokesman said Canonbie was one of a number of locations where Scottish Coal believed significant reserves remained, which could only be reached by deep mining.

That would require significant investment.

"The company are keen to support open-cast and deep mining - the problem is the economics and the politics," said the spokesman.

"Open-cast happens quite quickly but with deep mining you have to spend millions of pounds up front to put the shaft down.

Substantial reserves

"There are concerns that they would spend that money up front then government turns round and says coal is off the agenda."

Scotland's last underground mine closed in 2002.

Since then all coal mined in Scotland has been from open-cast sites.

A major exploration is already under way by a gas company in the Canonbie area to see if it could tap into coal bed methane.

It is believed there could be substantial reserves of methane trapped in coal seams deep below the surface.