A union representing public transport workers has written to Taoiseach Leo Varadkar and other party leaders calling for radical changes to Ireland's transport system.
The National Bus and Rail Union has said public transport cannot work with social distancing if it goes back to pre-Covid-19 norms.
It is calling for the Metro and BusConnects projects to be abandoned.
The NBRU said there will need to be significant changes to public transport systems to accommodate even reduced levels of morning and evening commuters.
It is suggesting staggered opening times for schools, colleges and workplaces and also for increased incentives for people to work from home.
It also proposes park and ride facilities around urban centres to reduce congestion and to facilitate more frequent bus services.
It argues that planning for future transport "should be based on what is achievable, not on what is desired".
To this end it says both BusConnects and the Metro in Dublin should be dropped and that Bus Rapid Transit systems could solve congestion in Dublin, Cork, Limerick and Galway at a fraction of the cost.
These would require dedicated roadways and priority junctions for buses.
It is also calling for a rail line to Navan, the completion of the Western Rail Corridor, a DART spur to Dublin Airport and the start of a Liffey tunnel linking Heuston and Connolly stations.
It says all of these projects could be completed within the lifetime of one government.
The NBRU is also calling for more space for walking and cycling and for accelerated trials of hydrogen and electric buses and trains.
The General Secretary of the NBRU has said the Covid-19 crisis has presented the opportunity to see how cities might operate with fewer cars in the future, if there was proper planning and consultation.
Speaking on RTÉ's Today with Sarah McInerney, Dermot O'Leary called for the Metro scheme to be scrapped saying there would be "better bang for your buck" if the Metro money was used for a variety of capital projects across the country, rather than a Dublin-centric project.
Mr O'Leary said a bus rapid transit system could be delivered, within five years, in Dublin, Cork, Limerick and Galway.
He added that there are parts of BusConnects that should be reassessed, not least the concept of widening the streets for the bus to operate alongside the car.
He said the NTA has stepped up to the mark in terms of providing personal protective equipment and cleaning buses but warned there will be a need for increased public transport capacity as people begin to return to work.
Mr O'Leary said there are around 70 Dublin buses that are "ready to be retired" that should be kept to augment the current fleet size.