A branch of the left-wing Momentum activist group has appeared to defend its use of an antisemitic placard to advertise a debate on Jew-hatred.

The Lewisham branch of the pro-Jeremy Corbyn organisation said the photograph of a banner claiming Hitler would be “proud” of Israel was intended to “challenge ideas in our movement”.

The image – reported by the Guido Fawkes website – was used in an online advert promoting the group’s debate on antisemitism and anti-Zionism on the left.

The placard states “Well done Israel – Hitler would be proud” and shows an Israeli flag with a swastika replacing the Star of David.

Speakers at the event next week include Momentum’s Jewish founder, Jon Lansman, and Jewish Labour activist Rhea Wolfson, who is hoping to be elected to the party’s National Executive Committee.

Momentum supporters criticised the advert and asked organisers to change the image, Guido Fawkes reported.

Mr Lansman told the website that he believed the photograph had been chosen “to illustrate a contemporary form of antisemitism, rather than endorse it”.

In a statement, Lewisham Momentum said: “Sure it is offensive, it isn’t very edifying… That’s the point of using such a photo that was taken on a protest that many of us were involved in.

“The discussion has to be had and we have to challenge ideas in our movement if we are to move forward and develop an understanding of different and specific kinds of oppression and racism.”