Minister for Transport Martin Cullen is to present the Government's 10-year strategic transport plan in Dublin Castle next Tuesday.
Invitations have been sent to key transport and regional development figures for the event, to be held in the State Apartments at 2pm.
The invitations have led to a flurry of speculation as to what the transport plan will contain, particularly in the west of Ireland where invitations have been received by campaigners for the reopening of the western rail corridor.
Hopes are high that Mr Cullen will announce the reopening of the line at least as far as Claremorris, Co Mayo, while keeping options open on the remaining link in the route from Claremorris to Sligo.
Campaigners in the west pointed out that National Development Plan spending in the Border Midlands and Western (BMW) region was well behind the State's southern and eastern region.
They said they were hoping their invitations signalled Government recognition that reopening the western rail corridor could represent a significant development initiative.
Tuesday's presentation of the transport plan will precede the weekly Cabinet meeting which has been held over from Tuesday because of the bank holiday weekend.
The plan already has the support of Taoiseach Bertie Ahern and Minister for Finance Brian Cowen.
As The Irish Times reported during the week, the re-establishing of passenger services on the western rail corridor between Ennis and Galway is virtually certain.
Sources also said the remaining sections between Athenry and Sligo could be reopened on a phased basis.
The plan, which has been costed at almost €20 billion, also includes:
r A commitment of almost €10 billion to complete the inter-urban motorway programme in the next five years
r Linking the Luas lines in the centre of Dublin with extensions to Swords, the docklands and Cherrywood
r A Dublin airport metro
r Iarnród Éireann's proposed station at Spencer Dock, a rail interconnector linking Connolly and Heuston stations via Pearse Street, and the reopening of the Navan railway line as far as Dunboyne, Co Meath
r Funding for the quadrupling of the Kildare route lines as far as Hazelhatch
r The expansion of commuter services on the Mallow line, and the reopening of commuter services on the Midleton line
r Improvements to inter-regional roads, particularly the western road corridor. Some provision for the outer orbital motorway route around Dublin.
Some of the costings in the plan are fluid, and it is noted that where money may not be required for certain projects at specific periods in the 10-year plan, it can be diverted to others.
"It is not just a matter of how much money, it is a matter of when it needs to be spent," said a Government source.
The plan represents more than a year's work on the part of Mr Cullen, who has secured important backing for the plan from Mr Ahern and Mr Cowen.
While Mr Cullen has repeated that there was no rift between his department and that of Finance, he has acknowledged that it was necessary for him and Mr Cowen to sign off on the plan.
Mr Ahern is expected to make the plan a major plank in the Government's manifesto for the general election due in 2007.