Jeremy Corbyn has defended controversial comments he made five years ago regarding a group of British Zionists not understanding “English irony” but said he is more careful with his language now.

The Labour leader faced criticism from the Tories and from the ranks of his own party on Friday after the last twist in the anti-Semitism row that has engulfed the party.

The Conservatives have reported Mr Corbyn to the standards watchdog over the comments made at the Palestinian Return Centre in 2013, claiming they breach the code of conduct and bring Parliament into disrepute.

In footage published on the MailOnline, Mr Corbyn accused a group of British Zionists who had criticised Palestinian ambassador Manuel Hassassian after an earlier speech of having “two problems”.

He went on: “One is they don’t want to study history, and secondly, having lived in this country for a very long time, probably all of their lives, they don’t understand English irony either.”

In a statement released on Friday evening Mr Corbyn said he had been defending the ambassador from “what I thought were deliberate misrepresentations” by people “for whom English was a first language, when it isn’t for the ambassador”.

Mr Corbyn said: “I described those pro-Israel activists as Zionists, in the accurate political sense and not as a euphemism for Jewish people – and that is made clear in the rest of my speech that day.

“I am now more careful with how I might use the term ‘Zionist’ because a once self-identifying political term has been increasingly hijacked by anti-Semites as code for Jews.”

Jewish Labour MP Luciana Berger had earlier said that the video contained “inexcusable comments” which made her feel “unwelcome in my own party”.

She wrote on Twitter: “The video released today of the leader of @UKLabour making inexcusable comments – defended by a party spokesman – makes me as a proud British Jew feel unwelcome in my own party.

“I’ve lived in Britain all my life and I don’t need any lessons in history/irony.”

She was supported by fellow Labour backbenchers, with Newcastle North MP Catherine McKinnell tweeting: “Standing right with you @lucianaberger.”

Sedgefield MP Phil Wilson wrote: “Right beside you @lucianaberger.”

In recent weeks, the Labour leader has come under increasing pressure over a number of issues linked to anti-Semitism and the Israeli-Palestinian conflict, including the party’s definition of anti-Semitism, his 2014 visit to a Palestinian cemetery in Tunisia and meetings with those connected to the Palestinian cause.

But senior Labour figures defended the party leader, with shadow chancellor John McDonnell saying he had devoted his life to securing peace in the Middle East.

Mr McDonnell told BBC Radio 4’s Today programme: “I think this has all been taken out of context: whatever Jeremy has said throughout the years has always been about how to secure peace, particularly within the Middle East and also peace with justice for all concerned – both members of the Jewish community and also members of the Palestinian community.

“In that context Jeremy has devoted his life, so I think this would take expressions out of context in that way are not helping.”

Helen Grant, the Tory vice chairwoman for communities, has written to Parliamentary Commissioner for Standards Kathryn Stone asking that Mr Corbyn be investigated over the comments.

Helen Grant’s letter to the Parliamentary Standards Commissioner asking her to investigate Jeremy Corbyn (PA)

The Maidstone MP argues it contravenes Clause 17 of the MPs’ code of conduct, which states: “Members shall never undertake any actions which would cause significant damage to the reputation and integrity of the House of Commons as a whole, or of its members generally.”

She said the comments had been branded “xenophobic and anti-Semitic” by the chairman of the Campaign Against Anti-Semitism, and praised by Nick Griffin, the former leader of the far-right British National Party.

She wrote: “Mr Corbyn has undoubtedly brought this House and its members into disrepute.

“This country has rightly always demanded more from our parliamentarians.

“It is clear that Mr Corbyn has not reached the bar set by the Code of Conduct for members, and I therefore ask that you investigate.”