The "vast majority" of donations made to Fianna Fail are not made in expectation of either favours or special access, the Taoiseach has said.
Launching the campaign yesterday of the Fianna Fail candidate, Mr Barry O'Brien, in the South Tipperary by-election, Mr Ahern challenged opponents to cite a single decision where the Government had acted corruptly.
Donations were made to the party because Fianna Fail governments benefited the economy, he said, and "if Labour receives less it should ask itself why".
Safeguards and legislation had been put in place and these could be tightened if necessary, but "we should not turn our whole democratic system upside down," he said.
"Political parties are voluntary organisations and should be entitled to fund-raise from both individuals and businesses, subject to the needs of transparency and accountability. I do not want to see State-run political parties."
He had no doubt rival parties would try to make tribunals an issue in the campaign, but the fact was that the Government led by himself and Mary Harney had governed with "honesty, decency and integrity".
"Mary Harney and myself came to politics with fewer advantages than most other leaders. There is not a single person of real wealth in the Cabinet.
"Things have happened in the past, when our political system was unregulated, which we repudiate, which were carefully concealed from almost everyone, and which are totally contrary to the ethos of this party. They may in some cases also have been in breach of the law, though that is not for us to determine."
The party was prepared to act in all cases involving current members "without fear or favour", he said.
Mr O'Brien, whose campaign slogan is "A Fresh Start", said it was to be regretted that the behaviour of a few had cast a shadow across the perception of politics generally. "I welcome and support efforts which have been undertaken to make those who have transgressed accountable, and put in place safeguards which will restore the respect politics should enjoy."
An indication of the heavyweight support Mr O'Brien can expect during the campaign was given by the presence of several senior Government Ministers, including Ms Mary O'Rourke, Mr Joe Walsh and Mr Frank Fahey.
Following the formal speeches Mr Ahern did a walkabout of Clonmel before opening a housing scheme on the Fethard road. The election takes place on Thursday, June 22nd.
Tipperary South
(1997 election)
FF 37.28% FG 24.09% Lab 16.11% SF 00.00% Other 22.52%
Elected: Noel Davern (FF) Therese Ahern (FG) Michael Ferris (Lab)