Regional Development Minister Conor Murphy will today publish a consultants' report which looks set to extinguish any chance of a light rail system like the popular Luas line in Dublin.

Three pilot routes are being considered for the busbased system one running from Dundonald through east Belfast to the city centre, another running from Titanic Quarter to Queen's University and the City Hospital and a third route from the city centre to the Royal Victoria Hospital and beyond to west Belfast.

Mr Murphy who has observed similar systems in the Netherlands said he would seek to supplement the 111 million of public funding by finding private sector money for the 147 million concept. The Sinn Fein minister will today launch a consultation process and has promised to work with the Regional Development Committee to develop the scheme.

Mr Murphy said: " The Programme for Government highlights rapid transit as a key priority, with a commitment to start work on the first scheme by 2011."

But University of Ulster academic Alan Woodside said the system was needed urgently and work should commence as soon as possible. The professor of highway engineering said: " We're light years behind Dublin on this and the difference is that they stopped talking about building the Luas system and actually built it.

"A bus system would take less time to build than the light rail option and we have the huge benefit of having Wrightbus on our doorstep a company that is selling these buses all over the world." But both the Alliance Party and the SDLP said they were dismayed that the minister appeared to be ruling out a light rail system which the Department of Regional Development ( DRD) said would cost 590 million.

Alliance deputy leader Naomi Long said: " If we are to be serious about rapid transit then we need a commitment to light rail. " In most comparable European cities light rail and tram systems form an integral part of the transport strategy. We need a transit system which is not just effective but also attractive enough to get people out of their cars."

SDLP deputy leader Alasdair McDonnell agreed and called for the Titanic Quarter line to extend further to the George Best Belfast City Airport: " Light rail has a higher capital cost but like the Luas in Dublin it has a good economic payback even in the mediumterm. "I would urge the minister to have courage and vision. In the longer term the current system of private car transport and gridlock is absolutely unsustainable and we need to invest in a system which can take all the potential passengers when the day dawns that commuters leave their cars behind."

East Belfast DUP MLA Robin Newton said he would also have preferred a light rail system but welcomed the fact that a form of rapid transport was being introduced. " It's critical that we get this system up and running as soon as possible to bring Belfast into the 21st century," he said. A DRD spokeswoman said it would try to give the rapid transit buses their own lane but said where that was not possible they would have priority at junctions.