The Department of Transport says target dates for delivery of individual projects in its €34 billion Transport 21 investment programme were merely "indicative".
The department was commenting after an Irish Times report yesterday outlined slippages with deadlines for 11 of 39 projects.
A spokeswoman said yesterday that while individual deadlines were indicative, the department was sure all projects would be completed "within the overall 10-year framework" of Transport 21.
The Labour Party yesterday called on Minister for Transport Noel Dempsey to make "an immediate statement" as a number of the earlier projects could not be delivered by the original deadlines.
Labour's environment spokesman Éamon Gilmore said clarification was needed because "delays in these projects not only have the potential to add significantly to the overall cost, but will also cause serious inconvenience for commuters".
Mr Gilmore recalled the original deadlines were outlined by Taoiseach Bertie Ahern, then tánaiste Mary Harney, Minister for Finance Brian Cowen and then minister for transport Martin Cullen at a ceremony in Dublin Castle.
At the time, he added, Labour had "questioned the capacity of the Government to deliver. This was not only because of the Government's poor record on similar projects in the past, but also because no costings were provided for any of the individual projects".
Mr Gilmore maintained that "major projects like the Port Tunnel and Luas turned out to be far more expensive than we were originally told and came in well after the promised date.
"Based on the details published today, it seems that the Government has not learned any lessons and the situation is as bad as ever."
Transport infrastructure providers have also moved to distance themselves from the original timetable. A spokesman for the National Roads Authority said phase one of the M50 upgrade had been approved by planners only in 2006 and had always been a two-year project.
As such, meeting the original completion date of 2007 was not possible. However, the spokesman said the work was going well and completion would be within a two-year framework.
He was echoing a spokesman for the Railway Procurement Agency who said its Luas extension to the Docklands had not been granted a railway order by the Government until the last week of 2006, meaning construction could not meet the Government's 2008 deadline.
Iarnród Éireann also said it had intended to begin its deployment of almost 200 new rail cars in 2007 and complete this in 2008, but he said the order could not have been completely deployed in 2007 as envisaged by Government.
AA spokesman Conor Faughnan said most projects appeared to progress well once construction began, but he believed many delays were still being experienced at planning stages.
