Former frontbencher Chuka Umunna has claimed that the Labour Party is an "institutionally racist" organisation.
Mr Umunna said it was a “very painful” admission, but vowed to stay as a Labour member because he felt it was better to “try and argue and see change through in an organisation” rather than “leave the field”.
He told Sky News’ Sophy Ridge On Sunday: “If you look at the definition of institutional racism as outlined by Sir William Macpherson in the Macpherson Report and the Macpherson Inquiry produced the institutional racism definition.
“The Labour Party, it’s beyond doubt for me that it has met it – it’s very painful for me to say that.”
The Streatham MP made the comments after being urged to apologise for saying Jeremy Corbyn should “call off the dogs” to stop centre-left MPs being driven out of the party.
Labour Party chairman Ian Lavery told the same programme that Mr Umunna’s call was “disrespectful” and “offensive”.
He said: “Calling anybody a dog is absolutely outrageous in the extreme, and Chuka Umunna of all people should know that.
“And I hope that when he comes onto your show this morning that he takes this opportunity of apologising to those people who he’s offended immensely.
“These are the people who keep Chuka Umunna and myself and other MPs in a job.”
Mr Umunna defended his remarks, saying: “The phrase that I used is a metaphor, it’s a figure of speech.”
Mr Lavery also said MPs should be “accountable” and expect to be challenged, after a number of Labour MPs who have been critical of Mr Corbyn, particularly over his handling of the anti-Semitism row, have found themselves locked in battles with members of their constituency Labour party.
Labour Friends of Israel chairwoman Joan Ryan, a former minister under Tony Blair, and Luton South MP Gavin Shuker, both lost local no confidence votes on Thursday.
But Mr Lavery, MP for Wansbeck, said: “These votes of no confidence hold no water, they are basically a statement from the constituencies.
“These aren’t individuals being targeted – they are being challenged.”
He added: “When people think that they are being unfairly challenged they need to be accountable to the people that they represent.”
It comes after former chairman of the Equality and Human Rights Commission Trevor Phillips claimed the Labour Party is “led by anti-Semites and racists”.
Mr Phillips, who served as a Labour member of the London Assembly for three years, told the Mail on Sunday that rows about anti-Semitism are “killing our party”.
Labour has faced accusations of anti-Semitism as senior figures have demanded the leadership take firm action to prove the party is not hostile to the Jewish community.
Mr Phillips said: “It doesn’t help that one of our great parties, the one I belong to, is led by anti-Semites and racists who basically want to eliminate anyone who disagrees with them.”
Mr Corbyn’s office said Mr Phillips’ comments were “wrong and offensive”, the paper reported.