Rep. Tom DeLay, R-Texas, a primary architect of the Republican majority who became one of the most powerful and feared leaders in Washington, told House allies Monday night he will give up his seat rather than face a re-election fight that appears increasingly unwinnable.

Officials told CNN and The Associated Press that DeLay also is likely to resign his seat and leave Congress by the end of May.

DeLay was expected to disclose his plans today, said the officials, who spoke on the condition of anonymity because the congressman had not made that announcement.

The decision came three days after his former deputy chief of staff, Tony C. Rudy, pleaded guilty to conspiracy and corruption charges, telling federal prosecutors of a criminal enterprise being run out of DeLay's leadership offices. Rudy's plea agreement did not implicate DeLay in any illegal activities, but by placing the influence-buying efforts of lobbyist Jack Abramoff directly in DeLay's operation, the former aide may have made an already difficult re-election bid all but out of reach.

Under Texas law, DeLay, who will turn 59 on Saturday, must either die, be convicted of a felony, or move out of his district to be removed from the November ballot. DeLay told Time magazine that he is likely to change his official residence to Alexandria, Va., by the end of May. He said he informed President Bush of his decision Monday afternoon.

"This had become a referendum on me," he told Time in an article posted on the magazine's Web site. "So it's better for me to step aside and let it be a referendum on ideas, Republican values and what's important for this district."

Democratic House campaign officials have been hoping to face DeLay in November, believing him to be the weakest Republican candidate they could hope for.

Sources close to DeLay said his decision was motivated by concerns that he might lose his suburban Houston seat to his Democratic opponent, former Rep. Nick Lampson, and his belief that another Republican could win instead. Once DeLay steps aside, the Texas Republican Party will choose a replacement candidate.

Troubling polls

DeLay got a temporary political boost last month when he fended off three challengers to win a Republican primary with 62 percent of the vote. But recent polls showed an uphill climb against Lampson and another former congressman, Steve Stockman, who had cut his ties to the Republican Party to run as an independent.

In early January, a Houston Chronicle poll showed DeLay trailing Lampson 30 percent to 22 percent, with Stockman taking 11 percent.

A December poll by CNN, USA Today and Gallup also indicated that a credible Democrat could beat DeLay.

However, Richard Cullen, DeLay's lawyer, said Monday evening that his client's decision to withdraw was "not connected to the criminal investigation."

Cullen said: "This decision was made before the Rudy plea. That didn't enter into it. It was personal and political."

DeLay's decision capped a long, difficult slide from power that began in September, when a Texas grand jury indicted him on money-laundering and illegal campaign finance charges. Under House Republican rules, DeLay had no choice but to relinquish his post as majority leader, but he vowed to beat the charges and quickly return to power.

In the ensuing months, the separate federal corruption probe stemming from Abramoff's activities drew closer to DeLay, first eliciting a guilty plea from DeLay's former press secretary, Michael Scanlon, then from Abramoff, whom DeLay once described as "one of my closest and dearest friends." Some House Republicans publicly stated DeLay could not be allowed to return to the House leadership if his implication in the Abramoff scandal appeared inevitable.

In January, DeLay abandoned his quest to regain the majority leader's post. At that time, however, he pledged to seek re-election, and he quickly snared a coveted seat on the House Appropriations Committee.

His renunciation of the leader's post touched off a scramble among Republicans eager to move past the DeLay era. A month later, Rep John Boehner, R-Ohio, upset DeLay's protege, House Majority Whip Roy Blunt, R-Mo., to win the highest position in the Republican conference, effectively ending the DeLay era of leadership that stretched back to Dec. 6, 1994, and the Republican Revolution.

An effective whip

When Republicans swept to power that year, DeLay capitalized on his fundraising prowess in a successful race for majority whip against Rep. Robert S. Walker, R-Pa. DeLay had been in Congress since 1985, and his fundraising largesse, especially with the huge freshman class of 1994, helped him overtake Walker.

DeLay became arguably the most effective whip in modern House history. He corralled Republicans into a lock-step discipline that blocked much of former President Clinton's agenda in the 1990s, engineered the impeachment of Clinton -- the first time a sitting president had been impeached in more than 100 years -- and later turned the House into President Bush's firewall against Senate Republican dissent.

Redrawing the maps

But his take-no-prisoners style did not begin to undermine his authority until 2002, when in an unprecedented power play, he jumped into Texas state politics to help secure a Republican majority in the state legislature, then personally pushed a redistricting plan to secure six additional House seats for his GOP majority.

The Texas redistricting fight is seen by some as a crowning political achievement, but also his undoing. Travis County's Democratic prosecutor, Ronnie Earle, secured an indictment on charges that DeLay solicited business contributions, then laundered them through Washington and into the coffers of Republican state candidates. Texas law forbids business donations to State House campaigns.

The indictment cost DeLay his leadership post, but the redistricted map may have cost him his seat. DeLay gave up some Republican strongholds in his district to help elect new Republicans in neighboring districts, bringing his own majority down to 55 percent in the 2004 election. This election year promises to be far more difficult.