Controversial pro-Palestinian vicar Rev Stephen Sizer has been banned from writing, preaching, teaching, emailing, tweeting, posting on Facebook or commenting in any way in relation to the current situation in the Middle East.

He has also been banned from doing anything at all on any social media for six months. He will instead now concentrate on his ministry as a parish priest.

Mr Sizer's promotion of an anti-Zionist agenda "is no longer compatible with his ministry as a parish priest," the Church of England ruled today. If he breaches his agreement to comment on the issue again, he has undertaken to resign as Vicar of Virginia Water, Surrey.

Mr Sizer has been at odds with Jewish community leaders for several years over his support for the anti-Zionist cause, but most recently caused further offence when he posted a link on his Facebook page to an article entitled The "9-11/Israel did it".

The article he linked to attempted to make connections between wealthy American Jews and the 9/11 attacks. Sizer asked online: "Is this anti-Semitic?.. It raises so many questions."

His diocese immediately pledged to investigate.

Today the Bishop of Guildford, Andrew Watson, said it was his view that Mr Sizer's "strong but increasingly undisciplined" commitment to an anti-Zionist agenda had become a "liability to his own ministry and that of the wider church."

He said that many who more moderately support the Palestinian cause, and share his critique of a particular brand of Christian fundamentalism, themselves find Mr Sizer's actions to be "increasingly unhelpful and counter-productive".

Bishop Watson said: "It is therefore my decision that Stephen's work in this area is no longer compatible with his ministry as a parish priest.

"In order for Stephen to remain in parish ministry, I have therefore asked for – and received from him – a solemn undertaking, in writing, that he is to refrain entirely from writing or speaking on any theme that relates, either directly or indirectly, to the current situation in the Middle East or to its historical backdrop."

The bishop said Mr Sizer had promised to refrain, with no exceptions, from attendance at or participation in any conferences which promote or are linked to this agenda and from all writing, tweeting, blogging, emailing, preaching and teaching on these themes, whether formally or informally. The prohibition includes posting links to other sites and from all background work in this area which may resource others to act as spokespeople in Stephen's stead.

Bishop Watson said: "Should Stephen be deemed by the diocese to have broken this agreement, in letter or in spirit, he has pledged to offer me his immediate resignation, which I will duly accept. He has also agreed to desist from the use of social media entirely for the next six months, after which he and I will review that prohibition."

Earlier, the Council of Christians and Jews said: "It is perfectly possible to criticise Israeli policies without such criticism being antsemitic, and Christians and others should feel free to do so. However, such legitimate criticism must not be used as a cloak for antisemitism, nor can antisemitism itself ever be disguised as mere political comment."

Bishop Watson said he did not believe Mr Sizer's motives were anti-Semitic. "But I have concluded that, at the very least, he has demonstrated appallingly poor judgment in the material he has chosen to disseminate, particularly via social media, some of which is clearly anti-Semitic.

"By associating with or promoting subject matter, which is either ambiguous in its motivation, or (worse still) openly racist, he has crossed a serious line. I regard these actions as indefensible."

The bishop said he welcomed Mr Sizer's apology and his recognition of the deep hurt caused by his actions, as well as his acknowledgement of the gross insensitivity of their timing just prior to Holocaust Memorial Day, and his retraction of the "ridiculous suggestion" that Israel may have been complicit in the events of 9/11.

Bishop Watson concluded: "Most importantly of all, I am hugely sorry for the hurt which has been caused to members of the Jewish Community, and I hope and pray that the storms of the past two weeks will ultimately serve to deepen and strengthen our relationship, one with another.

"This is a time when I would urge all Christian people to stand shoulder to shoulder with our Jewish brothers and sisters in countering the alarming rise of anti-Semitic incidents being reported, not least here in the UK. This is also a time for people of faith, Jews, Christians, Muslims and others, to work together in that open, robust partnership that will help to promote peace and justice in our communities, our nation and the wider world."

Jonathan Arkush, vice president of the Board of Deputies of British Jews, welcomed the actions.

Mr Arkush said: "The Board referred these matters regarding Rev Sizer to the Diocese of Guildford who have acted swiftly to resolve them. The Board has expressed its full acknowledgment of the undertakings asked of Rev Sizer and their implications and we are grateful that the Church shared our deep concern that Rev Sizer had indeed crossed a line in the offensive materials he was posting and linking to online.

"The Board of Deputies now hopes that Rev Sizer's unbecoming and inappropriate conduct has now been brought to a close. The Board together with the Diocese of Guildford and the Church of England strongly believe that good community relations are based on mutual respect and trust, which we now hope can be restored after this very unhappy episode."