A top Hamas representative has used a British newspaper to threaten action as an “immediate response” to the release of the Palestine papers.

Writing in the Guardian today, Osama Hamdan, described as the head of the Hamas international relations department, said a series of meetings have begun to “discuss practical measures”.

He was responding to reports published by al-Jazeera and the Guardian this week, allegedly based on leaked documents from the 2008 peace negotiations, which claim the Palestinians agreed Israel could keep most of east Jerusalem in return for an area beside the West Bank and a compromise on the question of refugees.

Osama Hamdan wrote: “As an immediate response to these revelations, we in Hamas have begun a series of communications and meetings with Palestinian factions and prominent personalities to discuss practical measures.

“It is our responsibility to regain the initiative in order to protect our cause and isolate those who have betrayed it.”

He claimed the alleged concessions were made because the negotiators “simply lacked any genuine affiliation to the people they claimed to represent”.

“They were making offers that, had they been accepted by the Israelis, would have represented the biggest act of treason in the regions history,” he said.

“It is unthinkable that the Palestinian people will ever approve any deal concluded with the Israelis by this team, for they will always be suspected of selling out and of betraying the cause.

“Our suspicion that the Palestinian Authority all along knew about and even conspired in the Israeli war on Gaza in late 2008 has now been confirmed by the documented testimony of both Israeli and Palestinian negotiators.”

Jon Benjamin, chief executive of the Board of Deputies, said: “The Guardian’s disproportionate obsession with Israel continued apace this week with today’s latest inclusion in the shape of an oped from a key member of Hamas.

"Offering such a substantial platform to an organisation defined as a terrorist body by the EU, the UK Government and by others surely places the newspaper’s journalistic credibility into question”

Michael Weiss, executive director of media monitoring organisation, Just Journalism, said: “The fact is that the acquisition of these documents by the Guardian has been carefully utilised by the newspaper to advance a radical agenda which goes far beyond ‘find[ing] out what is happening and report[ing] it’.

“They've given their comment section over today to a Hamas agent who, as Just Journalism uncovered, defends suicide bombings and advocates wiping Israel off the map.

“The Guardian has revealed itself incontestably as anti-compromise and pro-maximalist. For all its claims to be behind a two-state solution, its editorial decisions all point to the contrary.”

A Guardian spokeswoman said: “The comment piece by Osama Hamdan is one of a series of opinion articles we will be running in the Guardian and on guardian.co.uk in the coming weeks related to the Palestine papers.

“The pieces will present a range of opinions from all sides of this ongoing story, and we believe that to exclude the views of a single group - such as the piece by Hamas and their call for ‘a series of a communications and meetings’ - would be unrepresentative.”