U.S. Rep. Thomas M. Davis will not enter the 2008 race for the Senate seat retiring Republican John W. Warner is vacating, Republican officials said.

Davis, R-Va., is scheduled to make an announcement about his political plans Thursday.

There was no reply Tuesday evening to telephone and text messages left with congressional and political aides to Davis.

"He's out. He's going to be real coy about it, though," said one senior GOP official who spoke on the condition of anonymity because Davis has not made his plans public.

Davis, a moderate who has represented the Washington, D.C., suburb of Fairfax County since 1995, had expressed an interest in the seat.

His prospects for winning the Republican nomination, however, dimmed on Oct. 13 when the Central Committee of the state party voted to choose the nominee in a state convention next June instead of a primary.

The other likely Republican candidate is Jim Gilmore, a former governor whose tax-slashing policies won him a following in the party's conservative wing, a bloc which dominates state nominating conventions.

The eventual GOP candidate faces Mark R. Warner, a popular and wealthy Democratic former governor who announced his plans to run for the office on Sept. 13. In the 17 days of September after his announcement, Warner raised more than $1.1 million, according to federal campaign reports filed last week.

A Washington Post poll conducted earlier this month showed that Warner leads either Davis or Gilmore by 30 percentage points.

Davis has kept mostly silent about his political goals as he helps the campaign of his wife, state Sen. Jeannemarie Devolites Davis, R-Fairfax County, who is facing a fierce re-election challenge as the GOP struggles to retain control of its Senate majority in the Nov. 6 election.