Updated at 7:25 a.m. Feb. 3 by Kyung Song with statement from Reichert:

U.S. Rep. Dave Reichert, R-Auburn, will not run against Democratic U.S. Sen. Maria Cantwell this year, a high-level Republican source said Thursday.

For months, Reichert had remained coy about his plans, leaving open the option of a Senate bid. But he has decided to remain in the redrawn 8th Congressional District, which has grown more safely Republican thanks to redistricting, the source said.

A Reichert spokeswoman did not immediately respond to a call for comment Thursday afternoon.

For now, the leading GOP challenger to Cantwell is first-term state Sen. Michael Baumgarnter of Spokane, who has an intriguing resume, but lags badly in fundraising.

However, Port of Seattle Commissioner and trade consultant Bill Bryant is also said to be considering joining the race.

On Friday, Reichert's spokeswoman, Natasha Mayer, confirmed his decision but did not elaborate on his reason.

Reichert "is deeply committed to his constituents in Washington’s 8th district and looks forward to continuing his service to them from the US House of Representatives and his position on the Ways and Means committee," Mayer said in an email.