The Betws deep mine in Ammanford has had to lay off about 80 miners while the cause of the "technical problems" is investigated.

No one was injured and up to 30 staff are still working at the site to supply coal to customers from stockpiles.

But huge increases in insurance premiums could mean the workers are laid off for longer.

Martin Cook: "Safety is our top priority"

The fire happened on 9 July and the workers were laid off the following day.

On Tuesday, 16 July, Welsh Secretary Paul Murphy announced a special aid scheme, allowing the mine to continue operating, had been extended for a further five months.

Betws' managing director Martin Cook said he hopes to restart production as soon as possible.

'Tough decisions'

He said: "The workforce has been terrific. I have to make tough decisions in the short term to protect their long-term future.

"But there will be no resumption of production until I am entirely happy it is safe to do so."

Mr Cook added the colliery faces a parallel problem of a huge rise in employee liability insurance.

Customers are being supplied from reserves

The company pays £150,000 each year in insurance premiums but a recent one-week extension cost £30,000 alone.

He said: "Without this insurance, you cannot operate and it is a major concern.

"This isn't just a problem for us but right across the industry."

Mr Cook said he hopes the UK Government will intervene to help the industry.

The staff laid off will not be paid until they return to work.

The National Union of Mineworkers (NUM) secretary at Betws, Anthony Jones, said his members remained positive.

He said: "It's been disheartening for everybody not knowing how long this period of lay-off will last.

Private mine

"It comes as a great shock when people have been working in the industry for most of their lives and then the next minute all their income has gone.

"They are having to go down to the benefit agency to see what's available. "

Betws is a modern drift mine which opened in 1978 and was privatised in 1994.

It produces approximately 100,000 tons of coal each year for domestic and industrial use.

The company also supplies anthracite for specialist industrial filters.