The future of rail links to Londonderry and Larne is secure, Regional Development Minister Conor Murphy has made clear.
In an interview with the Belfast Telegraph, Mr Murphy said investment was being made in both lines, the future of which had been under threat in recent years.
He said: "The previous Executive took a decision not to spend money on what it saw as non-core lines.
"But the entire rail network is important, particularly if our overall objective is to reduce our carbon footprint.
"I think we have to look at all the remaining rail network as being core."
Confirmation that the NIR network is to remain intact marks the culmination of the long-running Belfast Telegraph Save Our Railways campaign.
The Telegraph raised the issue in April 2000 after Direct Rule Ministers claimed they could not afford the funding of £183m which was required over 10 years to keep all the lines open.
A petition attracted more than 12,000 signatures and in December 2000 the Assembly approved funding for new trains, track and signalling.
But since then, a threat continued to hang over the sections from Coleraine to Londonderry and from Whitehead to Larne, which were regarded as "non-core".
Martin Lindsay, editor of the Belfast Telegraph, welcomed Mr Murphy's comments and thanked Telegraph readers for the role they had played.
"This was a clear example of reader power and we are delighted that the message has got through," he said.
"The investment approved by the last Assembly for the rail network is paying dividends and the additional funding now proposed will build on that success."
The Minister cited as evidence of the Executive's commitment to public transport the decision to allocate cash in the draft Budget for new trains and upgrading tracks. Work is due to start in 2011 on a £64m two-year upgrade of the line from Coleraine to Derry, which will pave the way for a business case to be made for further investment, including a new passing loop at Limavady Junction, midway along the line.
The Minister said that in the more immediate future, some £12m was being spent on improvements to the Ballymena-Coleraine section, on parts of which trains are subject to speed restrictions of 10mph because of poor track.
Ultimately, the objective is to clip 30 minutes of the present journey time of two hours 10 minutes from Derry to Belfast.
Improvements are also under way on the Larne line, with part of the proposed package being new trains.
Mr Murphy said: " The existing rolling stock is being refurbished but that is not a long-term solution. But the objective is to acquire new trains for 2011.
" Translink's passenger figures show clearly that the numbers go up when you make an investment which improves comfort, frequency and reliability."
On the Larne line, work is under way on the construction of new park and ride schemes at Greenisland and Whitehead.