A new route for the Metrolink aimed at pacifying residents in south Dublin could see the Luas Green Line closed for up to four years, the Irish Independent has learned.
The proposal put forward by the National Transport Authority (NTA) is understood to involve bringing the metro underground through Ranelagh using a "cut and cover" technique.
However, the idea sparked such alarm in the Department of Transport that Transport Minister Shane Ross recently sought an immediate crisis meeting with the NTA and Transport Infrastructure Ireland (TII) to discuss it.
The route is being remodelled following complaints from some residents in Ranelagh who object to the closure of a road from Dunville Avenue to Beechwood Road to facilitate the metro.
The 'Rethink MetroLink South City' group says the plan would mean a "Berlin Wall" segregating communities.
The campaigners are backed by a number of high-profile politicians, including Housing Minister Eoghan Murphy.
A route from Swords to Sandyford, announced almost a year ago, proposed to have the underground line come above ground at the Luas Charlemont stop and then continue along what is currently the Green Line.
It is understood the NTA delivered alternative proposals to the minister in recent days.
Sources said Mr Ross met with the NTA and TII to "advise them both against the updated proposals which could see the Green Line closed for up to four years".
"Any plans which brings the Green Line to a standstill would be unacceptable," an insider said.
Under the original plan, the Luas would be disrupted for 18 to 24 months.
A spokesperson for Mr Ross declined to comment last night, saying it would be "inappropriate" at this stage.