Former Taoiseach Bertie Ahern has denied the issue of political donations was raised by developer Owen O'Callaghan during lobbying over tax designation.

Mr Ahern told the Mahon Tribunal he did not know Mr O'Callaghan had agreed to give Fianna Fáil £100,000 at a time he refused designation for a rival shopping centre development.

Mr Ahern says he cannot remember what was discussed with Mr O'Callaghan during a meeting in March 1994.

Mr O'Callaghan said Mr Ahern, then Minister for Finance, told him at the meeting that there would not be tax breaks for the rival Blanchardstown shopping centre.

Des O'Neill SC for the inquiry said Mr O'Callaghan was at the time concerned about the appointment of former EU commissioner Ray Mac Sharry to the board of Green Property, the development company behind Blanchardstown.

He asked Mr Ahern if Mr O'Callaghan would have told him that he had promised Mr Mac Sharry to give Fianna Fáil £100,000.

Mr Ahern replied it never happened that someone would ask for something at a meeting and remind him about a donation.

He said he did not know who was being approached for funding at the time because there were 'Chinese walls'.

Mr Ahern said he had heard about the Cork fundraising dinner but he did not know how much Mr O'Callaghan had contributed.

Mahon lawyers accused of agenda

Earlier at the tribunal, Senior Counsel for Mr Ahern Conor Maguire accused tribunal lawyers of pursuing an agenda against the former Taoiseach.

The accusation formed part of a series of exchanges between Mr Maguire and the tribunal in which he objected to certain questioning of his client.

Mr Ahern is giving evidence for a second day this week.

Questions this morning centred on a meeting between Mr Ahern when he was Minister for Finance in 1994 and the US based investment bankers Chilton and O'Connor.

Niall Lawlor, the son of the late TD Liam Lawlor, was involved with the firm and his name was used in correspondence to set up the meeting with Mr Ahern.

Chilton and O'Connor were hoping to help finance a new national stadium in Neilstown.

Mr Ahern said that at a reception in San Diego in 1994 he could not remember meeting Niall Lawlor or discussing his involvement with Chilton and O'Connor.

Judge Gerard Keyes asked Mr Ahern if he expected him to believe that he would not ask the son of a prominent Fianna Fáil TD what he was doing in the US.

Mr Maguire objected to the tone of questioning and the conclusions reached by the Judge.

He said the comments made by the judge were based on speculation.