Scotland's Energy Minister has warned the country's opencast mining sector faces destruction by proposals to charge a disproportionate fee to transport coal to England

The Office of Rail Regulation (ORR) is consulting on plans to increase track access charges for coal freight on a per-kilometre-travelled basis, just as the industry is reeling from the collapse of Scottish Coal and an estimated 600 jobs.

It would mean mines north of the Border paying more to transport coal to key markets in the south of England than those further south, Energy Minister Fergus Ewing has claimed.

While a preferred bidder has been identified to take on the assets of parent company Scottish Resources Group (SRG) and potentially create 500 jobs, a deal has yet to be secured.

Mr Ewing warned the ORR proposals have the potential to destroy the sector.

He added: "By far the biggest threat facing the future of the opencast coal industry in Scotland is the proposed increase in track access charges for coal freight.

"The ORR proposal is of grave concern due to the distance travelled element of the charge.

"The proposed charge will be levied on a per-kilometre-travelled basis, which means operators in Scotland that have a further distance to travel to the main markets in the south of England would be disproportionately affected, drastically undermining the competitiveness of the Scottish coal sector."

Mr Ewing said ministers have responded to the consultation by stating the charges could devastate the sector.

"The Scottish Government continues to respect statutory independence of the ORR in this matter, but it is vital that in reaching a decision on a charging regime the ORR should ensure that the wider impacts of these charges on the Scottish coal industry are fully considered," he said.

Hargreaves plc has been selected by liquidators KPMG as the preferred bidder for the former SRG business.

Mr Ewing said discussions between KPMG and Hargreaves were ongoing and the initial interest shown by Hargreaves was encouraging, describing it as a serious bid.

Labour MSP Ken Macintosh called for assurances that maintaining the maximum number of jobs in any buyout would be at the forefront of the Government's efforts.

"Given that we are talking about 600 jobs directly affected by the collapse of SRG, our first concern must be for those individuals, their families and others indirectly suffering as a result of the job losses," he said.

Conservative MSP Murdo Fraser welcomed the interest expressed by Hargreaves. He said: "I think that provides some assurance to at least some of the former employees of SRG going forward."

In February, The Herald reported that up to 150,000 more coal lorries per year will be forced on to Scotland's roads, risking a repeat of a crash that left a woman dead in her home.

The influx of vehicles will not only raise safety concerns but also impact on emissions and congestion, and cost up to 4000 jobs in Scotland after new charges are imposed on freight companies from 2016, according to the Freight Transport Association.

Catherine Bonner, 55, died in February after a lorry laden with coal ploughed into her flat in Fairlie, North Ayrshire.