HUNDREDS of Scottish mining jobs would be put at risk by plans to increase the charges freight companies pay for transporting coal by rail, the country's biggest producer has warned.

Scottish Coal (SCCL), which has a workforce of nearly 900 and operates eight open-cast mines in Scotland's central belt, said power stations would switch to importing coal from abroad if proposals made by Britain's rail regulator to more than triple track access charges from 2014 went ahead.

The effect on rural areas such as South Lanarkshire and East Ayrshire, which depend on what remains of Scotland's coal industry, would be sorely felt as mines closed and hundreds were forced on the dole, the firm warned.

Another effect would be to shift transportation to power stations from rail to road, leading to thousands of extra lorry journeys, increasing congestion and pollution, it said.

The warning has been made to Westminster's All-Party Parliamentary Rail Group, after Office of Rail Regulation (ORR) proposals to impose a higher levy on freight companies transporting coal used for electricity generation and spent nuclear fuel.

The proposals seek to lower the subsidies paid by the UK and Scottish governments to support the rail network by raising between £200 million and £250m a year from rail freight companies.

William Wishart, director of marketing and distribution for Scottish Coal, said the changes had the potential to force the "closure of all coal mines supplying the power generation market in England". Over half of coal extracted in Scotland is transported to England – all by rail.

He wrote: "Some 75% of SCCL direct employment is in rural areas such as South Lanarkshire and East Ayrshire.

"Any reduction in the workforce will be sorely felt as there are almost no other alternative employment opportunities."

He said the changes would also threaten government targets for reducing greenhouse gas emissions by increasing road haulage, which emits higher levels of carbon dioxide, and could overload rail deliveries from ports if more coal was imported by sea.

Despite the rise in renewable energy, coal accounts for 35% of UK-produced electricity, and more than half in the winter.

The rail industry has faced pressure to reduce taxpayer subsidies after a study by ex-Civil Aviation Authority chairman Sir Roy McNulty last year which called for savings of up to £1 billion by the end of the decade.

An analysis commissioned by the ORR found more than tripling track access charges could lead to a drop of up to 10% in the volume of coal transported by rail in the UK.

A regulator spokesman said it "wants to establish a fair and efficient approach to sharing the costs of using the rail network between freight and passenger operators".

He added: "ORR's consultation on rail freight charges highlights evidence which shows certain sectors should be taking on more of the costs of the tracks. ORR is keen to hear views and work closely with industries to balance such costs fairly for passengers, businesses and taxpayers."

A spokeswoman for Transport Scotland, the Scottish Government agency responsible for rail, said officials were yet to reach a final view, but added: "Scotland's rail freight network is important to Scotland's economy.

"The Scottish Ministers expect the ORR to pay due consideration to any changes to policy which may impact that network and employers, like the coal industry, who are dependent on the rail freight network."

The Rail Freight Group, an industry-backed lobby group, has also criticised the proposed hike in charges. In evidence to the All-Party Parliamentary Rail Group, it questioned the ORR's view the coal and nuclear industry would simply pay the higher rates.