DUBLIN, Ireland —  Irish Prime Minister Bertie Ahern, who helped broker peace in Northern Ireland but could not survive a scandal over his collection of cash from businessmen, announced Wednesday he will resign.

Ahern, flanked by his senior Cabinet ministers, told a news conference he would step down May 6. He denied ever receiving a corrupt payment, but conceded that 18 months of criticism of his financial ethics had taken a toll on his government's effectiveness.

"Never, in all the time I've served in public life, have I put my personal interests ahead of the public good," Ahern said during a 10-minute statement, during which his voice frequently wavered with emotion.

He said Ireland faced important challenges, including an expected June referendum on the European Union's next treaty, and the government must "not be constantly deflected by the minutiae of my life, my lifestyle and my finances."

"I have never received a corrupt payment, and I've never done anything to dishonor any office I have held. ... I know in my heart of hearts I've done no wrong and wronged no one," said Ahern, 56, who has been Ireland's leader for 11 years.

Ahern said he also planned to resign May 6 as leader of Fianna Fail, Ireland's dominant political party, which he has led since 1994. He vowed to continue fighting the accusations against him, and predicted the corruption investigation would conclude "that I have not acted improperly in any way."

But the leader of Ireland's main opposition party, Fine Gael chief Enda Kenny, said Ahern had suffered unprecedented public criticism as "a liar and perjurer," and had "bowed to the inevitable" because of his implausible testimony to an anti-corruption tribunal.

Kenny, whose rival coalition narrowly lost an election last year to Fianna Fail, called on his successor to mount an immediate general election. Analysts agreed this was unlikely.

Ahern's 2 1/2 terms in office have been marked by unprecedented economic success at home and peace in the neighboring British territory of Northern Ireland.

Tributes to his record of achievement flowed in, including from his most likely successor as both government and party leader, Deputy Prime Minister Brian Cowen.

Cowen — who unlike other Cabinet ministers was told of Ahern's decision Tuesday night — praised him as "a remarkable man who has achieved remarkable things for his country."

Former British Prime Minister Tony Blair, who built a close friendship with Ahern as they jointly oversaw key summits on Northern Ireland peacemaking, said Ahern should "be remembered for his crucial role in bringing about peace in Northern Ireland, for transforming relations between Britain and the Irish Republic, and for presiding over a sustained period of economic and social advance in Ireland."

Cabinet ministers said Ahern had given no hint — as they gathered Wednesday morning for their weekly meeting over breakfast — that he was about to announce an end to his Irish political career. Instead he discussed the day's government business, point by point.

Then he told them he was resigning and invited them to the news conference for the announcement.

"There was a shocked silence around the room. People genuinely did not expect it," Education Minister Mary Hanafin said. After Ahern gave the resignation statement, the Cabinet reconvened to finish the meeting.

Ahern's hold on power has been steadily weakening since investigators discovered cash payments he secretly received from businessmen in the mid-1990s.

After the Irish Times newspaper published leaked details in September 2006, Ahern claimed on national television and in parliament to have received just two major payments from personal friends totaling $96,000 in December 1993 and January 1994. He insisted he was broke at the time, but later admitted he already had an office safe full of money and a bank loan.

The investigation since has uncovered about a dozen undocumented cash deposits running up to December 1994 allegedly involving Ahern, who is due to resume testimony next month.

The total 1994 value of these disputed deposits — in accounts controlled by Ahern, his daughters, his former girlfriend or his local party office — now exceeds $880,000.

Ahern has repeatedly denied a central accusation in the investigation that he received five-figure payments in both U.S. dollars and British pounds.

The killer blow appeared to come last month, when Ahern's former office secretary was reduced to tears on the stand as she denied, then admitted, taking $30,000 — all in British currency — to deposit in accounts controlled by Ahern and his two daughters on one day in 1994.

The leaders of the two other parties in Ahern's coalition government, the left-wing Greens and the right-wing Progressive Democrats, called last week for Ahern to issue a statement explaining the contradiction in evidence. It was the first expression of public discord in their 10-month-old government.

Ahern then declined and avoided public appearances — until Wednesday.

He said he wanted to remain in office until he delivers a speech April 30 to the joint houses of U.S. Congress in Washington. He said that speech would be "one of the proudest moments of my political career."

Several Cabinet members called on Ireland to laud, not lampoon, Ahern in the coming days. They said Ahern was too young to retire — and instead was a likely candidate for a higher-profile job on the international stage.

Ireland's major bookmaking company, Paddy Power, lost no time in taking bets on Ahern's next job. Gamblers strongly backed the possibility that Ahern might be appointed as the first permanent president of the 27-nation European Union.