Five TDs have accused Tánaiste Eamon Gilmore of double standards regarding the detention of 14 Irish activists in Israel as they tried to bring aid to Gaza.
Members of the United Left Alliance have written to the Labour leader calling for the Israeli Ambassador to Ireland Boaz Modai to be expelled over their arrest at sea.
Socialist MEP Paul Murphy is one of 14 Irish activists being held in Givon prison awaiting deportation after being detained on board the MV Saoirse in international waters.
The TDs, Independent Seamus Healy, Socialists Joe Higgins and Clare Daly, and People Before Profit's Richard Boyd Barrett and Joan Collins, said the Tánaiste must demand the activists' release.
"If any other country acted in this fashion against Irish citizens the pressure on you to condemn outright such an action would be considerable," the TDs told the Tánaiste.
"However different standards seem to apply to Israel in the world of international diplomacy.
"Frankly the response of the Government has been disgracefully lacking and you personally must take a large share of the responsibility."
It is understood the 14 did not want to participate in a trail in the Israeli courts which has added to deportation delays. Irish consular staff in Israel are providing assistance.
The 14 crew of the MV Saoirse and the crew of Canadian vessel Tahrir where detained by Israeli military in international waters as they made their approach to the port of Gaza last week.
They are being charged with illegally entering Israel.
Mr Boyd Barrett added: "This was an act of piracy in international waters where Israel has no legal jurisdiction."
The TDs have demanded that the Tánaiste condemn the Israeli actions.
The Saoirse and Tahrir were towed to the port of Ashdod by Israeli military, which has described the incident as a peaceful takeover. This description is disputed by the crews of the boats, however.
The 14 detainees also include People Before Profit councillor Hugh Lewis and Dr Fintan Lane, a co-ordinator with the Irish Ship to Gaza campaign who was arrested in a separate attempt to bring aid to Gaza in 2010.
Fianna Fáil leader Micheál Martin has demanded the immediate release of the passengers.
It is understood the Israeli authorities are arranging repatriation flights for the Irish activists within the next 48 hours.
A spokesman for the Department of Foreign Affairs insisted the Tánaiste has spoken out strongly against the detention.
"We are providing all possible assistance we can. We are seeing the detainees on a daily basis. The Tánaiste has been very strong in what he said," the spokesman said.
Mr Gilmore discussed the group's detention direct with the Israeli Embassy in Dublin.