Activist Shane Dillon who was seized by Israeli authorities in a commando operation which left at least 10 people dead on an aid flotilla is being sent back to Ireland.
Six other Irish campaigners - including Dr Fintan Lane and Fiachra O Luain - are being detained in the Be'er Sheva detention camp, where they face deportation.
The three named activists were on board Free Gaza boat Challenger 1 which was boarded by Israeli forces in international waters as it travelled from Cyprus.
Nobel peace prizewinner Mairead Maguire remains on board the Irish-owned vessel MV Rachel Corrie, which the Israeli navy is preparing to stop.
Irish Foreign Affairs Minister Micheal Martin, who maintains that the Irish citizens were kidnapped, confirmed the Irish ambassador in Tel Aviv was finally given permission to meet Mr Dillon at Ben Gurion Airport before his departure.
The ambassador and officers from the Irish Embassy in Tel Aviv are also due to visit the detained Irish citizens.
"I will continue to press for full consular access being allowed, as is provided for under international law," said Mr Martin.
"I will be reporting to the Government later this morning on my meeting yesterday with the Israeli ambassador and on the measures which my department is taking to secure the immediate and unconditional release of those Irish citizens detained by Israel."
The UN Security Council has also called for the immediate release of all the ships and citizens detained by the Israeli authorities.