Sen. Pat Toomey (R-Pa.) will not seek reelection or run for governor of Pennsylvania in 2022, two sources confirmed to The Hill.

Toomey called Senate Majority Leader Mitch McConnell (R-Ky.) to inform him of the decision, the sources added.

Toomey, 58, is currently the only non-judge Republican holding statewide office in Pennsylvania after a string of Democratic victories in 2018. First elected in 2010, he won reelection in 2016, beating Democratic challenger Katie McGinty by about 1.7 percentage points.

Toomey was considered a top contender on the GOP side for the 2022 gubernatorial race, due in large part to his public stances on state government issues such as Gov. Tom Wolf’s (D) handling of the coronavirus pandemic. He has also fundraised for GOP state attorney general candidate Heather Heidelbaugh, who is running against Attorney General Josh Shapiro (D). Shapiro is himself seen as a top Democratic gubernatorial candidate in 2022. The lack of an heir apparent for the Republican nominee in either race could lead to a prolonged intraparty fight, The Philadelphia Inquirer noted.

Toomey is a longtime advocate for term limits and signed a pledge endorsing a constitutional amendment to limit senators to two terms. In December, however, he declined to rule out a third term, telling NBC’s “Meet the Press” that “I have not imposed term limits on myself.”

Republican senators will already be on the defensive in 2022, defending 22 seats, compared with 12 Democratic seats.

The senator’s office did not respond to a request for comment but has said Toomey will make an “announcement regarding his future political plans” on Monday morning.