A senior trade unionist has been called on to apologise for plugging a film about a left-wing activist who was kicked out of Labour after being accused of anti-semitism.

Lynn Henderson, a top official in the PCS trade union in Scotland, wrote that she was “very proud” of the filmmaker behind a documentary that portrayed Jackie Walker as the victim of a witch hunt.

Walker had been expelled from Labour after saying she had not heard of a definition of anti-semitism that she could work with.

Scottish Tory MSP Annie Wells said: “Lynn Henderson needs to explain this expression of support. And she could do a lot worse than apologise to Scotland’s Jewish community who have been through quite enough.”

Walker, who used to be vice-chair of the left wing Momentum group, was suspended by Labour in 2016 over comments about Holocaust Memorial Day at a party training event.

“In terms of Holocaust day, wouldn’t it be wonderful if Holocaust day was open to all people who experienced holocaust?” she said.

After it was pointed out that Holocaust Memorial Day does mark other genocides, Walker said:

“In practice, it’s not actually circulated and advertised as such.”

She added: “I was looking for information and I still haven’t heard a definition of antisemitism that I can work with.”

Walker also questioned why Jewish organisations, such as schools, said they needed high security:

“I was a bit concerned by…. your suggestion that the Jewish community is under such threat that it has to use security in all its buildings.

“I have a grandson, he is a year old. There is security in his nursery school and every school has security now. It’s not because I’m frightened or his parents are frightened that he is going to be attacked.”

She had previously been suspended, then readmitted to Labour, after writing that Jews were “chief financiers of the sugar and slave trade” and claiming that “the Jewish Holocaust does not allow Zionists to do what they want”.

Her comments about Holocaust Memorial Day led to another suspension and an investigation that took over two years to resolve.

After her case was referred to Labour’s national constitutional committee (NCC), which has the power to sanction members, Walker was expelled for “prejudicial and grossly detrimental behaviour against the party”.

A Labour spokesperson said at the time: “The NCC has found that the charges of breaches of party rules by Jackie Walker have been proven.”

However, filmmaker Jon Pullman made a documentary about Walker’s case - called “Witch Hunt” - in which she was portrayed as a victim.

Henderson, who used to be president of the Scottish Trades Union Congress, tweeted about a screening of the film in Glasgow:

“Thank you @CamGuerillas for hosting the showing of Witchunt in Glasgow last night. I am very proud of my filmmaker friend Jon Pullman.” Her tweet included an image of the film.

On the PCS website, she is listed as the union’s full time officer in Scotland and the national officer for Scotland and Ireland.

The online blurb for the film states: “In 2015, while the far right was gaining ground around the world, socialist MP Jeremy Corbyn was elected as leader of the UK Labour Party in a landslide victory. Accusations of antisemitism within the party immediately began to circulate. Well-known anti-racists and left-wing Jews, such as Jackie Walker, were amongst the chief targets.”

The one-hour film included extensive contributions from Walker and interviews with figures who back her.

Asked whether she had tweeted in a PCS capacity, Henderson said: "No. Jon Pullman has been a personal friend of mine for many years."

Filmmaker’s reaction: Herald on Sunday letters