Green Party leader Eamon Ryan says he believes a proposed Cork to Limerick motorway would "make no sense".
Mr Ryan appeared on Newstalk Breakfast this morning, for a leaders' edition of 'Your Call'.
He said he believes the future of transport in Ireland is rail - and that a planned motorway between Cork and Limerick "makes no sense" to him.
He argued: "[The motorway] is a huge expense and it will not work... I'd far prefer to invest in the rail systems in both Cork and Limerick.
"If there is a need for an upgrade to the Cork-Limerick road system, I think it's far better and cheaper to do it if you join the existing N7 and allow for traffic to work that way.
"If you want to build up Cork and Limerick, you build in Cork and Limerick
"I don't believe that the big overblown Fine Gael motorway plans make sense, and we would use the money instead to fund public transport."
He added: "We have an existing rail network - we have a very extensive network.
"We're going zero-carbon, so the entire rail network has to be electrified.
"As we're [electrifying], I'd prefer to double the rail tracks on the existing lines: then the towns on those - all over the country, which have stations - thrive.
"Everyone knows that the current car-based transport system is not working - not just for the planet, but also for the people."
Asked about a potential coalition after next month's vote, Mr Ryan said it's essential that climate change doesn't become a divisive party political issue - confirming they'll talk to any party if necessary.
He said: "I've been saying this for four or five years now - the scale of change we need to make on climate is so huge... it will take three or four governments to do it.
"If we're going into the politics of doing this saying 'we talked to one side and not the other'... how are we going to do it over three or four governments?
"Look at America, where they've turned this into a divisive issue - it does not work. Look at the mess Australian politics is in on climate.
"If this is rural vs urban divide, or young vs old divide, or left vs right divide, we will not make the leap."
Mr Ryan was also asked about his views on the direct provision system.
The Dublin Bay South politician said he believes we need to provide housing for asylum seekers as well as our own people.
He observed: "We need to change away from the current system, which is cruel and provides hardship on those people seeking refuge here.
"[We need] a combination of different alternatives - you will have certain centres where people come for very short term periods.
"It's [about] getting people in, getting the asylum process done much more quickly, and allowing them to move on."
Main image: Eamon Ryan with Shane Coleman and Kieran Cuddihy