An Oireachtas committee has heard that Ireland must accept the "simple fact" that Israel is engaged in apartheid, if the Republic is to retain "any moral authority".
The head of Amnesty Ireland also warned that governments failing to call out Israel will find themselves "on the wrong side of history".
The Joint Committee on Foreign Affairs and Defence was hearing from Amnesty International on its report "Israel's Apartheid against Palestinians".
The Government must "acknowledge the established fact that Israel is perpetrating the crime against humanity of apartheid against Palestinians," Colm O'Gorman, Executive Director of Amnesty International Ireland, said.
"That's critically important," he added. "We must be able to honestly name what is happening, and then work to hold those to account who are responsible for such crimes".
"Any state that wants to retain moral authority" must challenge Israel on its failure to uphold international law, he said.
Last year, Human Rights Watch also concluded that Israel is guilty of apartheid, as did Israeli human rights group, B'Tselem.
Even before Amnesty's report was published this month, the Israeli Foreign Minister Yair Lapid dismissed it as "just another radical organisation that echoes propaganda with no serious examination."
The Taoiseach Micheál Martin has said that "the Government does not use the term apartheid", Mr O'Gorman said.
"This is not a term - it is not a turn of phrase", he insisted. "As a matter of law, the crime of apartheid is being committed".
Mr O'Gorman called on the Government to "get behind the Occupied Territories Bill", as enacting it would be "a big step, a brave step".
The bill would ban trade with illegal settlements, including Israeli settlements in the Occupied Territories, and was introduced by Independent Senator Francis Black.
Although not a member of the committee, she was allowed to participate, and said when she was drumming up support for the bill in meetings across Ireland, there were people "hanging out of the rafters".
She thanked Amnesty for highlighting the contrast between Israeli settlements - with "palm trees, shopping centres, swimming pools" and fountains, "like Florida" - and Palestinians living "around the corner in absolute deprivation and poverty".
Saleh Hijazi, who authored the Amnesty report, is based in East Jerusalem and Ramallah.
Joining the committee via video-link from South Africa, he said that there are "over thirty" case studies in the report on which Amnesty has campaigned for over twenty years.
Each one relates to a specific location where human rights are being systematically denied, he said.
Mr Hijazi told the committee that as a Palestinian citizen of Israel, his citizenship does not extend to his wife, and so they have to use different airports when travelling internationally.
He flies out of Israel's Ben Gurion Airport, while his wife has to drive to neighbouring Jordan and fly from there.
And if the couple want to visit relatives in Jerusalem, she has to apply for a permit, which is "a degrading, humiliating and dangerous" process.
Sorca Clarke, Sinn Féin TD, said the report ensures that "there can be no longer a defence of ignorance".
Two Fine Gael members of the committee, Chair Charlie Flanagan and Senator Joe O'Reilly, strongly defended both the committee's work on this issue and the performance of Minister for Foreign Affairs, Simon Coveney.
Richard Boyd Barrett, Solidarity-PBP, who is not a member of the committee, had also requested to be allowed to appear.
He welcomed the forensic detail in the report, and said that Israel had been an apartheid state "since its foundation".
A visit to a Palestinian refugee camp in 1987, after having worked on an Israeli agricultural settlement, had made this clear to him, Deputy Boyd Barrett recounted.
And he warned that the two-state solution would institutionalise apartheid and so "perpetuate that system".
The Dáil will discuss the Amnesty report next week, following a request from Deputy Boyd Barrett.
