Ian Austin has become the ninth Labour MP in a week to quit Jeremy Corbyn's party, claiming there was a "culture of extremism, anti-Semitism and intolerance".
The Dudley North MP said he was quitting the "broken" party and was "ashamed" of what it had become under Mr Corbyn.
But the former minister said he had no plans to join his eight former colleagues in the Independent Group they established this week.
In an interview with the Express & Star newspaper he said: "The Labour Party has been my life, so this has been the hardest decision I have ever had to take, but I have to be honest and the truth is that I have become ashamed of the Labour Party under Jeremy Corbyn."
He added that "I could never ask local people to make Jeremy Corbyn prime minister", and said he was "appalled at the offence and distress" the party had caused to Jewish people.
"It is terrible that a culture of extremism, anti-Semitism and intolerance is driving out good MPs and decent people who have committed their life to mainstream politics," he said.
"The hard truth is that the party is tougher on the people complaining about anti-Semitism than it is on the anti-Semites."
Mr Austin added that "the hard left is now in charge of the party" and "I just can't see how it can return to the mainstream party that won elections and changed the country for the better".
His resignation follows those of eight other MPs who quit Labour and formed the Independent Group.
But Mr Austin said he had not spoken to the group, which also contains three ex-Tories.
"I think the Labour Party is broken and clearly things have to change but that's not what today is about, and I've not talked to them about that," he said.
Labour called for Mr Austin to quit as an MP and contest a by-election.
A Labour Party spokesman said: "We regret that Ian Austin has left the Labour Party.
"He was elected as a Labour MP and so the democratic thing is to resign his seat and let the people of Dudley decide who should represent them."
Former Labour MPs Luciana Berger, Chuka Umunna and Chris Leslie - who left to form the Independent Group earlier in the week - offered support to Mr Austin after his announcement.
Ms Berger tweeted: "I fully understand why @IanAustinMP has come to this difficult and painful decision."
Mr Leslie wrote: "Full respect for @IanAustinMP and his difficult decision to leave @UKLabour today. Politics is broken and it is so important MPs stand up for the mainstream values we share. #ChangePolitics".
And Mr Umunna posted: "Massive respect to @IanAustinMP for making this incredibly difficult decision - it's painful and hard but he has stayed true to his values and what he believes to be the national interest."
Mr Austin has indicated he has no plans to join their group.