In March 1970, Jiryis was one of the initiators of a hunger strike by Palestinian administrative detainees, which attracted wide support, including demonstrations in Israel and across the world.
[citation needed] About 1975, Yasser Arafat sent Jiryis together with Issam Sartawi to Washington, D.C. to open an office to represent the Palestine Liberation Organization (PLO).
However, Henry Kissinger, then the Secretary of State, working in coordination with Yitzhak Rabin, then the Israeli Prime Minister, sent the FBI to the Capitol Hilton Hotel to deport Jiryis and Sartawi.
[citation needed] About the same time, Israeli doves General Mattityahu Peled, Uri Avnery and Arie Eliav had been meeting for months in Paris, France, with Jiryis and Sartawi.
[citation needed]During the 1982 Lebanon War, the Palestine Research Centre's historical archives were seized by occupying Israeli forces, but were returned as part of the November 1983 prisoner exchange with the PLO.
"'My brother is a very secular man, affiliated with the PLO's centrist stream, who believes in peace talks and a two-state solution for two nations,' he told Haaretz, and added: "What they are trying to ascribe to him contradicts his political outlook.