Jeremy Corbyn has said he regrets not looking more carefully at an allegedly anti-Semitic image before giving his apparent support to the artist responsible for it.
The Labour leader was challenged by some of his own MPs over his response to a Facebook post by the street artist Mear One about the plan to paint over the work.
Mr Corbyn's response suggested the artist was "in good company" because the Rockefeller family had covered over a mural featuring Lenin in their New York development.
Tomorrow they want to buff my muralFreedom Of Expression. London Calling,Public art
In his post responding to the imminent destruction of the mural, Mr Corbyn said: "Why? You are in good company. Rockerfeller (sic) destroyed Diego Viera's mural because it includes a picture of Lenin."
But Mr Corbyn has now acknowledged he should have looked more closely at the image before posting on Facebook.
He said: "In 2012 I made a general comment about the removal of public art on grounds of freedom of speech. My comment referred to the destruction of the mural Man at the Crossroads by Diego Rivera on the Rockefeller Center.
"That is in no way comparable with the mural in the original post. I sincerely regret that I did not look more closely at the image I was commenting on, the contents of which are deeply disturbing and anti-Semitic.
"I wholeheartedly support its removal.
"I am opposed to the production of anti-Semitic material of any kind, and the defence of free speech cannot be used as a justification for the promotion of anti-Semitism in any form. That is a view I've always held."
The statement from Mr Corbyn came after a backlash against his initial response, issued through a spokesman.
"In 2012, Jeremy was responding to concerns about the removal of public art on grounds of freedom of speech," the spokesman said.
"However, the mural was offensive, used anti-Semitic imagery, which has no place in our society, and it is right that it was removed."
Labour MP Luciana Berger - who highlighted the post by Mr Corbyn - hit out at the "wholly inadequate" response.
She said: "It fails to understand on any level the hurt and anguish felt about anti-Semitism. I will be raising this further."
Luton South MP Gavin Shuker said: "It's impossible to confront anti-Semitism in our party if this is the response from the very top."
The Jewish Labour Movement said: "Anti-Semitic art is anti-Semitism.
"History is littered with imagery that has reaffirmed the worst kinds of racial stereotypes and led to the worst kinds of racial discrimination.
"It cannot be defended under any circumstances. Not by anyone and least of all the leader of the Labour Party."
The mural, in east London, was painted by Mear One - whose real name is Kalen Ockerman - and depicted a group of businessmen playing a Monopoly-style game on a board balanced on the backs of people.
The artist denied being anti-Semitic, saying the mural is about "class and privilege" and contains a group of bankers "made up of Jewish and white Anglos".