The Seder Night themes of captivity and freedom took on a new twist in thousands of Israeli households this year, with the launch of a new haggadah remembering Jonathan Pollard.

The Freedom Haggadah, sub-titled "Let's not pass over our brother Jonathan", was produced and distributed by activists campaigning for America to free the spy.

Pollard started serving a life sentence in a US prison in 1987, for passing military secrets to Israel while working as an intelligence analyst for the US Navy.

The all-Hebrew haggadah urged Seder hosts to leave a chair at their table empty for Pollard and read out a letter on the subject of the holiday that he wrote.

Some 20,000 copies were given out in return for donations by pro-Pollard activists nationwide.

The haggadah contains the full text of the standard Seder service, along with reprints of passages that have been published in various forums in recent years calling for Pollard's release. Most claim that the sentence is too long given that he was spying for an ally not an enemy, and relate campaigning for his freedom to the halachic injunction to free captives.

The release of the haggadah reflects the growing enthusiasm for Mr Pollard's cause in right-wing religious-Zionist circles, and a desire to integrate calls for his freedom into religious practice.

"Since the late 1990s this has become a very big cause for right-wing Israelis, especially in the religious community," said Ben Gurion University political scientist Fred Lazin, an expert on Israel-US relations. However among the mainstream "there are so many things happening and this case just kind of gets lost."

In 2003 former Sephardi Chief Rabbi Mordechai Eliyahu composed a special prayer for Mr Pollard, which is recited regularly by many individuals and congregations.

Just before George W Bush left office last year, Chief Rabbis Yona Metzger and Shlomo Amar presided over a mass prayer rally for his freedom at the Western Wall.

The haggadah is a compilation of rabbis' writings on Pollard, together with the full Seder service and an introduction in which the editor, Gabi Kadosh, claims remembering Pollard on Passover is appropriate as he "sacrificed his freedom for me, for you and for all of us".

This year, politicians also decided to draw a connection between Passover and Pollard. Members of all Jewish parties except Meretz signed a letter to US Vice President Joe Biden, drafted by the mostly religious Zionist National Union party, asking him to "to show mercy to Jonathan Pollard who is so sick, and to grant him clemency as a humanitarian gesture to the Jewish People, to mark the Festival of Passover, the Festival of our Freedom".

Israeli leaders, when they meet US officials, routinely ask for Mr Pollard's freedom, but experts believe that this has become a formality, and that popular support for him is not adequate to make his case a serious issue.

The haggadah was the initiative of Rabbi Gabi Kadosh, municipal rabbi of the northern Negev town Shomriyah and other pro-Pollard activists in the town.