Taoiseach Bertie Ahern has been given permission by the High Court to challenge certain aspects of the Mahon Tribunal's inquiries into his financial affairs.
Lawyers for Mr Ahern claim the tribunal has no entitlement to cross-examine him about statements he made in the Dáil, even if similar statements had been made by him outside the house.
Mr Ahern is also claiming that advice given to his legal advisers by his banking expert, Paddy Strong, is privileged and does not have to be produced at the tribunal.
His lawyers also say Mr Ahern is entitled to all the financial calculations carried out by the tribunal to support the hypotheses that bank lodgements of US$45,000 and STG£25,000 were made on behalf of Mr Ahern in late 1994.
They say Mr Ahern needs access to all this financial information in order to effectively present his case to the tribunal.
Mr Justice Bryan McMahon ruled that Mr Ahern had made an arguable case in relation to all three issues.
He granted a stay on an order made by the Tribunal directing Mr Ahern's legal advisers to produce documentation relating to Mr Strong's advice by this afternoon.
That issue has been adjourned until Thursday afternoon when the tribunal will have a chance to respond.
Mr Ahern is due to give evidence before the tribunal again on the 21 and 22 February.
His senior counsel, Brian Murray, said his client was not trying to interfere with that scheduled appearance.
A full hearing of the Taoiseach's challenge to the tribunal will take place at a later date.
Meanwhile, Fine Gael leader Enda Kenny has accused the Taoiseach of attempting to frustrate and delay the work of the tribunal.
He said that the Taoiseach cannot claim to be co-operating with the inquiry when trying to dictate to it what questions it can ask him.
