Half of British publishers are refusing to take books by authors who are identifiably Jewish, a literary agent has claimed.

The major agent, who did not wish to be identified, said many mainstream publishing houses were among those deeming Jewish books as off bounds.

The agent was speaking to Stephen Games, who founded the independent publisher EnvelopeBooks, who said it has been an “emerging problem” for some time that has been “exacerbated” since the Israel-Gaza war began in October.

“A very well-known literary agent of great repute and associated with books that one would immediately recognise said that he is having difficulty with his Jewish authors or writings on Jewish subjects because he just finds that much of literary London is now a no-go zone for Jews,” said Mr Games.

“He said there is no point putting proposals up to commissioning editors as they just are not interested.”

Mr Games said there was “a climate of growing hostility against Jews” but he was “not surprised by it”. There are fewer than 300,000 Jewish people in the UK, which has a population of 67 million.

“The first problem is those people who say ‘this affects me, Jews control the world and Zionists have this evil, Western, capitalist, conspiratorialist plot to control the world and they’re using Muslims because they stand in the way of Western domination’,” he said.

“All of that is supported by well-meaning Middle Englanders who are terribly sympathetic and buy into the craziness of this political rhetoric that’s spouted.

“Then there’s this third element now who say ‘I don’t have any stake in the game here but just don’t want to be bothered by other people saying, hey, you’ve run a piece about Jews and I don’t like what you’re doing’.

“It’s an amazing expansion of the problem now.”

One of those with direct experience of the problem is Gillian Freedman, 67, an author whose book Jews Milk Goats – about a couple maintaining a Jewish way of life while being a smallholder – was due to be reviewed by a columnist for an online magazine.

But she claims that the columnist was told to remove mention of the book by an editor, who said: “In the current, rather febrile, atmosphere I think we need to give a wide berth to anything which references Jewish people and Judaism. It just isn’t worth the hassle that will ensue.”

Likening the current situation to “bookburning”, Ms Freedman said that her community in rural Bedfordshire is more inclusive than London – contrary to the view that cities are more liberal.

“I’m very open about being a Jew in my little village and I’m very well accepted and integrated and have had a lot of support – much more support than my Jewish friends in London have had, many of whom are no longer speaking to people they thought were friends because of the perceived and actual anti-Semitism,” she said.

The warning comes after a group of 175 people from more than 15 different publishers and agencies formed Book Workers for a Free Palestine “to organise for the academic and cultural boycott within the book industry of companies complicit in Israeli apartheid”.