Opposition politicians are calling on the Taoiseach to raise the issue of CIA 'torture flights' with US President George W Bush this St Patrick's Day.
Anti-war activists say aircraft involved in the controversial CIA 'extraordinary rendition programme' have landed at Shannon Airport on numerous occasions in recent years.
The CIA uses the programme to kidnap suspected Islamic militants and transfer them to secret prisons across the world where critics claim they are being tortured.
The Government has said it accepts assurances from the US government that no such prisoners have been on board any flights passing through Shannon.
However, peace campaigners want the Irish authorities to go further and inspect US flights to make sure Irish territory is not being used for illegal activities.
The Peace and Neutrality Allianc e has arranged a special "fly-in protest" today whereby a plane carrying politicians opposed to the US use of Shannon will fly from Dublin to the Co Clare airport.
Labour Party TD Joe Costello, who will be one of those on board, said he wanted Mr Ahern to seek a guarantee from Mr Bush on Friday that Ireland was not being used as part of the rendition scheme.
He said the Irish State had an international obligation to ensure that no 'torture flights' were passing through its territory.