Pro-Palestinian activist Lauren Booth has launched a vitriolic attack on the Palestine Solidarity Campaign for dissociating itself from antisemitic musician Gilad Atzmon, saying the central office should be working "to end Zionism".

Her comments highlight the internal divisions in the PSC, between the national body and its more radical branches. Last week, PSC director Sarah Colborne said the organisation had "no links with Atzmon and does not work with him."

In response, Ms Booth, a recent convert to Islam and the half-sister of former Prime Minister Tony Blair's wife Cherie, wrote on her blog: "Britain is witnessing the rise of a new wave of pro-Palestinian activists. They need an organisation that is fit for purpose. One that does not pander to the emotional whims of the Jewish, Zionist lobby."

She added: "The PSC is ...attempting to create a pro-Palestinian organisation that does not hurt Zionist sensibilities. Campaigns of appeasement to the Israeli lobby can never, ever, co-exist as part of a determined campaign to end Israel's bloody and illegal occupation of Palestine. Let us be clear. A Palestine Solidarity Campaign should be working to END Zionism. Not ease it a little. Not work alongside it."

Ms Booth, a presenter with Iranian-funded Press TV, praised Mr Atzmon's new book, The Wandering Who? because it "pulls no punches, when asking to what degree the racist ideology - Zionism, when mixed with the Jewish sense of 'Chosenness' - is to blame for the existence of today's apartheid Israel."

She criticised blogger Anthony Cooper, who monitors PSC groups for instances of Holocaust denial and antisemitism. Mr Cooper said: "It's encouraging that the PSC appears to have decided to take the problem of antisemitism seriously and is taking steps to dissociate itself from those who deal in hatred of Jews. They have a lot more to do but the early signs are promising".

CST director of communications Mark Gardner commented: "This article is ugly and ridiculous, but very usefully illustrates how Gilad Atzmon's emergence is forcing the anti-Israel movement to acknowledge its antisemitic demons; and then oppose them, or explicitly refuse to care."

Jewish anti-Zionist and PSC activist Tony Greenstein called Ms Booth's attack "venomous" and said it was "based on a core racist commitment." He wrote on his blog: "PSC needs to take decisive action to root out, once and for all, those who evince sympathy for racism - of whatever description. Gilad Atzmon is deeply antisemitic. He subscribes to every myth and libel that has ever been written about Jews, from the world Jewish conspiracy theory, to the Protocols of the Elders of Zion to the Holocaust itself. "

Board of Deputies chief executive Jon Benjamin said: "The question isn't whether the PSC will implode, but whether those within the trade union movement, the churches and NGOs, where the PSC have gained traction, will now see it for what it is, a nasty, rejectionist organisation that has no interest in peace and reconciliation between the Israeli and Palestinian people."