Peter Robinson: "More funding needed"

However, there is speculation that 700 workers could lose their jobs if the railway closes due to lack of investment.

But in a statement on Wednesday, Mr Robinson said the railway system in Northern Ireland had suffered from serious underfunding for decades.

"I have to make it clear that I will not compromise the safety of the travelling public," he said.

"Urgent decisions have to be taken in the light of the AD Little safety report involving the Department of Regional Development, Northern Ireland Transport Holding Company and Translink."

He said that the task force set up by Mr Ingram was expected to make an interim report by the end of July, outlining its assessment of all the possible outcomes.

He added: "The fact is that I have a presumption in favour of maintaining and enhancing the railway system and there needs to be an extremely strong case put forward for me to change my mind."

He said that there were a "number of options" and he hoped a case could be made to ensure this "very important form of transport" could be retained.

"The one certainty is that more funding will be required regardless of whatever option is chosen, however, no decisions will be taken ahead of consultation with the public, the DRD assembly committee and the assembly," he said.

Translink says rolling stock badly needs updated

Earlier, Translink managing director Ted Hesketh said workers should use the opportunity given to them to make their views known.

He said that the profitable Enterprise Belfast to Dublin service was the only one not under threat.

However, he said, this could be taken over by a Dublin-based company.

"Translink staff, both rail and bus, kept public transport operational through 30 difficult years," he said.

"They have earned the right to engage in the debate surrounding the future of the railway. It is important they take advantage of this opportunity."

Task force

He added that it was unfair that NIR received less government funding than some privately-funded services in the UK.

"It was Minister Ingram who first raised the possibility of railways closures.

"There should be much more emphasis on the need for the task force to secure the proper level of funding for a modern public transport system.

"The government has acknowledged historic under-investment.

"It is well established that NIR receives only a fraction of the public support given to the privately-owned rail companies in Great Britain."

The Progressive Unionist Party said it was concerned that the letter from Mr Hesketh "paints a very bleak future".

The Alliance Party's Eileen Bell said she was worried about underfunding of the railways.