WASHINGTON -- Democrat Manan Trivedi is planning a third run for Congress, hoping that the retirement of U.S. Rep. Jim Gerlach (R., Pa.) provides the opening he needs.

Trivedi will launch a campaign Tuesday, he told the Inquirer Monday afternoon. He'll run for the Chester County-based seat long-held by Gerlach, who is not seeking re-election.

"I think this is a great opportunity to get a refreshing change in this district," Trivedi, 39, said in a telephone interview.

Trivedi's decision sets up a Democratic primary involving two veterans. Michael Parrish, a businessman and former Army aviator from Malvern, is already in the race, making his first-ever run for public office.

Trivedi, a physician who lives in Birdsboro, was formerly a batallion surgeon in the Navy.

Parrish has been in close contact with national Democrats and has gotten off to a fast fund-raising start, according to his allies.

In a statement, he said he looks forward to "a spirited discussion" about "creating more economic opportunities for the middle class."

"I have confidence that voters in the primary will select the strongest nominee to ensure a Democrat wins this very tough district in November," Parrish said. Parrish is a former Republicans, though his allies see his party-switch as an advantage -- a measure of his independence in a moderate district.

Trivedi plans to announce his campaign Tuesday along with a list of local endorsements. He said he has yet to begin raising money for the run.

On the Republican side, Chester County Commissioner Ryan Costello is the only candidate in the race. He said he is listening to residents and focusing on the economy. "Who my opponent is isn't my focus," he said.

The open seat and narrowly-divided district has created the potential for one of the tightest races in the Philadelphia region. While the district leans slightly Republican, it is one of the most politically balanced in the country, featuring moderate voters on both sides.

Trivedi ran for the seat in 2010 and 2012, losing both races to Gerlach 57-43.

"An open seat is a much different race," Trivedi said Monday. "I think we'll get a much fairer shot, a much more level playing field."

Trivedi said he hopes to focus on jobs. He called for more investment in infrastructure and education.

Parrish similarly touted the importance of education and the economy when he launched his campaign in January.

Republicans painted the Democratic contenders as one (Trivedi) who has "twice lost this race by double digits" and one (Parrish) "who was a lifelong Republican voter and donor that became a Democrat solely to run for Congress."

"It should be interesting to watch these two trip over each other trying to run from Obamacare," said Ian Prior, a spokesman for the National Republicans Congressional Committee.

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