The Campaign Against Antisemitism has asked the High Court to reject the libel claim brought against it by veteran anti-Zionist Tony Greenstein. 

Mr Greenstein sued the CAA in early 2018 over a series of five online articles that described him as a “notorious antisemite” which appeared between July 2017 and January 2018. 

One article also said he had lied to the Guardian by claiming the International Holocaust Remembrance Alliance definition of antisemitism prevented criticism of Israel. And also that he had lied to the Charity Commission by claiming the CAA was a right-wing political Zionist organisation that was not concerned with fascist groups who were Holocaust deniers. 

Representing the CAA at a one-day hearing, Adam Speker QC said there was “very little dispute” over what Mr Greenstein had written on Twitter and elsewhere. 

The issue did “not require the court to grapple with arguments over the correctness of the international definition of antisemitism”, he said. 

The issue was whether an honest person could hold the opinion that Mr Greenstein was antisemitic. 

Citing as one example comparisons made by Mr Greenstein of Israeli policy to the Nazis, Mr Speker said there were “few things as offensive to the vast majority of Jews”. 

But Mr Greenstein’s counsel, David Mitchell, argued that the case should go to full trial rather than be dealt with by a summary judgment. 

 The IHRA definition had been “misapplied and misused in order to attack him for political reasons, not on the basis that he is antisemitic”.

The IHRA defintition did not render him an antisemite "when properly read," he said. 

He noted Mr Greenstein’s view on the IHRA in the Guardian had been as one of 62 signatories of a letter– over half of whom were Jewish. “An honest person would not believe that these 62 signatories had all conspired to lie in a letter published in a national newspaper,” Mr Mitchell said. 

The CAA also asked for the dismissal of claims of misuse of private information and breach of data protection for mentioning Mr Greenstein’s previous convictions. 

Mr Mitchell said the petty offences had been spent over 30 years ago and reference to them was gratuitous. 

But the CAA argued that this was justified in relation to its claims that Mr Greenstein had lied. 

The judge reserved her judgment.