The Department of Transport has unveiled five possible routes to link the two LUAS tram lines in Dublin.
Three of the proposed routes cross the Liffey at O'Connell Bridge and continue down Westmoreland Street and College Green, while the others would require the construction of a new bridge.
The Government is now inviting views from the public before deciding on which option to choose.
Minister for Transport Martin Cullen has said he expects construction on the line to begin at the end of next year and be completed by 2009.
The Government had been widely criticised for constructing two unconnected LUAS lines in the first place.