MADISON, Wis. (AP) — Mega-donors on opposite sides of the Republican U.S. Senate race in Wisconsin are planning what appears to be a unity fundraiser three days after the Aug. 14 primary.

The conservative website RightWisconsin first reported on the fundraiser Monday. The chairs of the event are Beloit billionaire Diane Hendricks and Illinois billionaire Richard Uihlein. Hendricks backs state Sen. Leah Vukmir in the Senate primary while Uihlein is behind Kevin Nicholson.

The event is a signal that the billionaires plan to unite behind whoever wins the Republican primary.

Wisconsin Republican Sen. Ron Johnson has tried to urge GOP unity in the race and is one of the guests at the Aug. 17 fundraiser along with Sen. Cory Gardner of Colorado, chairman of the National Republican Senatorial Committee.

The winner of the primary will face Democratic Sen. Tammy Baldwin.