The leader of Fine Gael, Mr Michael Noonan, yesterday refused to criticise his predecessor, Mr John Bruton, for failing to inform the Moriarty tribunal of the Telenor payment.
Mr Noonan said the former Taoiseach had taken legal advice which made it "quite clear" he was not obliged to report the cheque to the inquiry.
"But having reviewed the situation," Mr Noonan said, "I am taking a different view - that it is prudent now, taking all the circumstances into account, to fully apprise the Moriarty tribunal of these events."
Speaking on RTE's News at One, he said he had already drafted a letter from the party's solicitors which he hoped to post to the tribunal by evening time.
The whole affair, he said, "shows that corporate donations are bad for politics. They raise suspicion all the time and I think they have to be banned."
He added: "I doubt very much that Fine Gael was the only party that received donations from telecommunications companies and I would like Fianna Fail and all others to also advise Moriarty of any donations they got."
Mr Noonan said he first learned of the issue last Sunday and had since made a full disclosure. He said he was aware of inquiries in the previous weeks from the Sunday Tribune, which reported the story.
He had spoken informally with the chairman of Fine Gael's trustees group, who told him there had been a donation from Mr Denis O'Brien which had been returned but had since come back.
He said he wished to return the payment to Telenor, although he acknowledged neither the company nor Mr O'Brien seemed willing to accept it. Both Telenor and Mr O'Brien, he said, had been treating the payment as "a hot potato since 1998, since Telenor first came to our general secretary accompanied by their legal adviser. . . . Bad publicity is bad for business and they are nervous, in my view, that bad publicity will ensue and, of course, bad publicity is ensuing over the last 24 hours."
Mr Noonan said the case underlined the fact that "it is impossible in modern politics to distinguish between donations from business which are given to support democracy and donations from business which seek influence.
"It is embarrassing for the political parties and it is time for a new mandate and the only mandate possible is no corporate donations and very low limits for personal donations."