Democrats Lt. Gov. Ralph Northam and former congressman Tom Perriello are set to make the case to progressive activists and labor groups.
Northam and Perriello are scheduled to meet at the International Brotherhood of Electrical Workers union hall in Richmond for their third debate.
Northam is the party establishment favorite and is being supported by outgoing Gov. Terry McAuliffe and U.S. Sens. Tim Kaine and Mark Warner, both former Virginia governors. Perriello is running an insurgent campaign with the backing of U.S. Sens. Bernie Sanders and Elizabeth Warren.
Virginia's gubernatorial race is getting national attention as one of the few 2017 campaigns that will shed light on the electorate's mood under the presidency of Donald Trump.
The primary is set for June 13.