Islington Council had banned Gilad Atzmon from playing with the Blockheads at a performance at the Islington Assembly Hall tonight.
They said the 55-year-old saxophonist’s appearance alongside Ian Dury’s former band “might harm” relationships with the north London borough’s religious communities.
Mr Williamson, a former shadow minister under Jeremy Corbyn, posted a link to a petition to get him reinstated this morning, alongside the caption: “Hands off Gilad Atzmon - sign the petition!”
After social media users and Jewish groups expressed their anger, he deleted the message and posted an apology instead.
The Derby North MP said: “Earlier today I tweeted a petition about an Islington Council ban against the Blockheads performing with their chosen line up. The council has blocked jazz musician Gilad Atzmon from playing with the group.
“Since then I’ve learned that Atzmon, a former Israeli soldier, is not confined to the jazz world.
“I am told that in various blogs and in speeches he has adopted anti-Semitic language.
“I wasn’t aware of this until after I tweeted the petition.”