Construction would begin on a new M5 East tunnel during the first term of a Labor government, Opposition Leader Luke Foley says.

However, Mr Foley would only say he "hoped" construction would begin in the next four years on another M4 East motorway, the other major road project Labor says it would build.

Luke Foley backs half of WestConnex project: Opposition Leader outlines Labor's transport and infrastructure plan. Credit:Brendan Esposito

Releasing the opposition's transport and infrastructure plan on Thursday, Mr Foley distanced the Labor Party from WestConnex, the government's series of motorway projects from western Sydney through the inner west.

"WestConnex is a brand, it's not a roads policy," Mr Foley said. "I'm not going to buy the brand because it's not a good brand."