But they are clinging to the hope that a scaled back project could get the green light in the not-so-distant future.
A new light-rail system could be tabled as part of a wider plan that will incorporate the Dart interconnector, sources say.
Some observes believe that delays and controversy around Metro North means its brand is now perceived as "negative" and needs to be changed.
A number of TDs in the Dublin North and Dublin North West constituencies have conceded to the Herald that they don't expect the existing plan to go ahead.
One government TD described Metro North as "highly unlikely in the foreseeable future".
And major pressure is expected to be mounted on Minister James Reilly after seemingly rowing back on his previous firm stance on the issue.
In an interview last year, the Fine Gael Deputy leader attacked the Labour Party over its policy to push back the project if elected to government.
"So much for Labour Party's policy of investing in infrastructure and jobs. When Labour are presented with a project that would deliver 37,000 jobs in the economic corridor along the proposed Metro North route they turn it down," he said in a pre-election interview.
However, Mr Reilly now appears to have changed his stance, stating this week that "funding problems need to be addressed in order to move this project forward".
The decision on whether the project gets the go-ahead is likely to be made in September.