Mr Foley's conduct has long been a source of concern on Capitol Hill, Mark Beck-Heyman, told The Washington Post. The former aide, who had worked as a congressional page in 1995, said that he had been warned by another page to steer clear of Mr Foley.

“Many people on Capitol Hill have known for over 11 years about what was going on and chose to do nothing,” the Post quoted Mr Beck-Heyman as saying.

As far back as 1995, Mr Foley was learning the names of the teenagers, sending them notes, letters and e-mails and asking them to join him for ice cream, the newspaper reported.

President Bush today broke his public silence on Mr Foley, saying he was "disgusted" and "disappointed" by his actions.

Mr Bush’s comments came as the Republican Party struggled to contain the political damage triggered by the scandal, weeks ahead of November’s midterm elections. The affair continued to gain momentum, spurred by new claims about the extent of Mr Foley’s inappropriate communication with teenage aides.

Mr Foley, 52, has already resigned his seat in the House of Representatives and has checked into a rehabilitation clinic amid an FBI investigation into online messages in which he discussed masturbation with a boy.

Last night messages were released apparently showing he had 'internet sex' with one boy before going to vote in the House. ABC News obtained a transcript from 2003 during which the politician and the high school student both appear to have orgasms while exchanging messages.

Mr Foley added yet a further twist to the story when his lawyer confirmed longstanding rumours that his client is homosexual and said he had been sexually abused by a clergyman at the age of 13 to 15. The lawyer insisted that the congressman, who was known as a champion of children’s rights, had never had any physical sexual contact with an underage male.

Dennis Hastert, the House Speaker and one of the party’s most powerful figures, is now fighting for his political life after the disclosure of evidence showing that he knew about inappropriate communication between the Congressman and pageboys almost a year ago.

In his first comments on the matter, Mr Bush last night said: "I was dismayed and shocked to learn about Congressman Foley’s unacceptable behaviour. I was disgusted by the revelation and disappointed that he would violate the trust of the citizens who placed him in office."

The President said he fully supported the call by Mr Hastert for a full inquiry into the matter. "This investigation should be thorough and any violations of law should be prosecuted," he said.

Mr Bush did not respond to questions over whether Mr Hastert should resign, but said he was "confident he will provide whatever leadership he can to law enforcement" in regard to the investigation into Mr Foley’s actions. Defending Mr Hastert, Mr Bush said: "He’s a father, teacher, coach who cares about the children of this country."

The right-wing Washington Times, as well as some conservative radio talk show hosts, yesterday demanded that he resign — even as Mr Hastert’s aides embarked on a frantic ring-round of other Congressman who were asked to sign a letter of support.

Mr Hastert brushed aside any suggestion of resignation. But he has admitted that he "would have, could have, should have" done more to discipline Mr Foley when he first heard about the e-mails.

John Boehner, the House majority leader, appeared to pull the rug from under Mr Hastert when said that the incident had happened on the Speaker’s watch and that he had assured him months ago that the matter had been taken care of it.

Mr Boehner also appeared to write off the chances of Republicans holding Mr Foley’s Florida seat in mid-term elections on November 7. The Democrats need 15 net gains to take control of the House and six to take over the Senate.

Some Republicans expressed fears that further revelations regarding the foibles of other politicians were yet to come. “People are very, very concerned,” said Ray LaHood, an Illinois Republican. “I think there are going to be more disclosures.”

The Arlington Group, a coalition of 70 pro-family conservative groups, said: “We have heard rumours that other, similar activity has occurred involving additional congressmen and will be released prior to the November elections.”

Political analysts say that the revelations could convince many conservative voters to boycott the elections altogether, with several polls putting the Democrats as favourites to win back a majority in the House.

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