Candidates for Boston Mayor are making a last pitch to voters ahead of the city’s preliminary election on Tuesday.

Acting Mayor Kim Janey, city councilors Annissa Essaibi George, Andrea Campbell and Michelle Wu, and John Barros, the city’s former economic development chief, are all vying to be one of the two top vote-getters in the contest.

Candidates’ public schedules show a wide range of last-minute campaigning, from greeting commuters at MBTA stations to local radio interviews to get-out-the-vote rallies with prominent community members and political figures.

Wu has topped all recent polls, but Janey, Essaibi George and Campbell are in a statistical dead heat for the other slot in November’s runoff election. Polling analysis by the MassINC Polling Group suggests that the level of turnout will be key to which candidate will move on to the final round. The two top candidates on Tuesday will face off against each other on Nov. 2.

The future of real estate development in the city and the high cost of local housing have been top issues in the race, with candidates espousing a range of views, but many have proposed ideas that would lead to liberalizing the permitting process for affordable housing projects or multifamily developments near transit, more generally.

The campaign marks a pivotal turning point in the city’s history. The preliminary election will almost certainly for the first time narrow the field of mayoral contenders to two candidates of color, possibly both women.

Wu’s parents immigrated to the United States from Taiwan. Janey and Campbell are Black. Essaibi George describes herself as a first generation Arab-Polish American. Barros is of Cape Verdean descent.

Throughout its history, Boston has only elected white men as mayor.