U.S. Rep. Fred Upton said Thursday he is endorsing former state Sen. John "Joe" Schwarz in the Republican primary for southern Michigan's 7th District congressional seat.

"Here's a guy with real experience that can step into the job on day one," said Upton, a Republican who represents the neighboring 6th District. "I think he would feel very comfortable in the job and be a good voice for all those who live in that district."

Schwarz is one of six Republicans vying for the nomination in the Aug. 3 primary. Another is Brad Smith, an attorney and son of U.S. Rep. Nick Smith. Nick Smith currently holds the 7th District seat but is stepping down later this year.

Nick Smith took a swipe at Upton Thursday for not endorsing his son in the primary, saying "it sure seems awkward that he would do that."

"Fred is the leader of the left wing of our House of Representatives so it's not surprising to me that he would endorse a liberal in this race," Nick Smith said.

Upton pointed out that he also endorsed Schwarz in 1992 when Schwarz ran unsuccessfully against Nick Smith. Upton said he won't criticize the other candidates in the race, but feels strongly that Schwarz has the most experience.

Upton has recorded a radio ad about Schwarz for the Republican Main Street Partnership, a group that supports moderate GOP candidates. The ad began airing Thursday and will run through the Aug. 3 primary, the group said.

Republican U.S. Reps. Vernon Ehlers and Mike Rogers, who also are in nearby districts, said Thursday they have no plans to endorse candidates in the 7th District race.