Owen Smith has accused Jeremy Corbyn of failing to do enough to tackle homophobic bullying in the Labour Party.
Former leadership contender Angela Eagle has said Mr Corbyn failed to intervene as she suffered abuse and was called “Angie the Dyke” after she challenged him for the top job.
The Labour leader has said the abuse is “absolutely and totally wrong”, but Mr Smith accused him of being “complacent” and failing to get a grip on the problem.
In a question-and-answer session with Pink News streamed over the internet, Mr Smith said the abuse is “appalling and unacceptable”.
He said: “I think Jeremy’s response to the charge that people have been abused - women in the Labour Party, Angela for her sexuality - has been quite often to say, ‘well I’ve been abused too... and often the best thing to do is ignore it’.
“I don’t think that’s the best thing to do, especially if you’re the leader of the Labour Party. The best thing to do is address it. And as leader of the Labour Party, addressing it means stating clearly, publicly, that we have got zero tolerance for it, that your party has zero tolerance for it, and you will make sure you stamp it out.
“And anybody found guilty of that sort of abuse in the Labour Party should be kicked out.”
He added: “I think he (Mr Corbyn) has been complacent about misogyny, about anti-Semitism, about homophobic abuse in the Labour Party. I don’t think he has been strong enough in speaking out against those things and doing something about it.
“It is not enough to say ‘ignore it’, you have got to address it and deal with it.”
Mr Smith warned there is “increasing intolerance” in Britain and warned that is being mirrored in the Labour Party.
He said: “I think we have got to be honest...there is clearly a rising tide of hate speak and hate crime of all sorts and homophobia and biphobia and transphobia are all featured in there, and it is clear there are rising incidents.”
He added: “For us to be reflecting that and not seeking to mitigate, go up against it, for us to be having to answer questions about homophobia or any other sort of abuse in the Labour Party, is completely wrong.
“We should have zero tolerance, we should be the party that speaks for decency and tolerance and celebration of diversity in the country.”
Mr Smith also criticised his leadership rival for being paid up to £20,000 for appearing on the Iranian news channel Press TV and suggested he should give the money back.
Mr Corbyn was quizzed by Pink News readers in a live-streamed session on Wednesday, during which he defended the appearances claiming he was able to “raise a number of human rights issues”.
But Mr Smith criticised his rival for taking the payments, saying: “I’ve not taken any money from any other source other than my parliamentary salary in the six years I’ve been an MP and I think that’s appropriate.
“I think we get paid enough for doing our jobs and I don’t think we need to get paid extra money for doing jounalism.”
He added: “I don’t know why Jeremy felt he needed to take any money.”
Asked what he thinks Mr Corbyn should do, Mr Smith said: “Well, he could always give the money back.”