Tom Watson: Racist bullies drove Luciana out of the Labour Party

Ms Berger is one of eight former Labour MPs who have quit to join the new Independent Group over Jeremy Corbyn's approach to Brexit and anti-Semitism.

The split – which has also seen three Tories join the group – has prompted a degree of soul searching among some Labour MPs, with Mr Watson calling for a reshuffle so the front bench better reflects all views in the party.

The West Bromwich East MP, who was hosting a phone-in show on LBC radio, was asked whether he was considering leaving Labour and joining the new group of MPs.

He replied: "I felt shamed when Luciana Berger felt she had to leave. She was driven out by racist bullies and that is completely unacceptable in any liberal democracy.

"But I still think the Labour Party is the century-old vehicle that can change lives and give voice to ordinary working-class people whose voices are not heard by the powerful.

"That's why I am so disappointed they have gone and that's why I really want people to stay and fight their corner."

Mr Watson said that the eight MPs who resigned from Labour were "valued colleagues" and that it was "a time for reflection and sadness in the Labour Party".

He said that the majority of Labour members were not involved in "harshness, brutality and bullying", but added: "There are some new members – a tiny number – that I think are harsh and bullying in their views."

Asked by a caller why he stuck with Mr Corbyn, Mr Watson said: "I'm sticking with him because, as a Labour Party member for over 35 years, we are a broad movement with half a million members who democratically elected him twice.

"I still think the vehicle for social change in this country that has delivered progress for working people without a voice is the Labour Party."

Mr Watson told the caller, who said he had quit Labour when Mr Corbyn took over: "You may not like Jeremy as leader, but if you genuinely believe in a fairer society and you want to fight racism, come back into the party and fight with me.

"We will fight those anti-Semites, we will deal with those bullies, we will bring half a million Labour Party members together and we will go out on the doorsteps and try to make this party electable.

"One anti-Semite in the Labour Party is one too many and I'm going to fight them all the way until they are removed from whatever position they hold in this party."