Tom Watson has announced that he is stepping down as deputy leader of the Labour Party.
In a shock announcement, Mr Watson said that he would not be seeking re-election as an MP in the forthcoming General Election.
In a letter to Labour leader Jeremy Corbyn, he said that the time had come to “start a different kind of life”.
“The decision is personal, not political,” he said.
“The last few years have been among the most transformational of my personal life, second only to becoming a proud father of two beautiful children.
“I’ve become healthy for the first time and I intend to continue with this work in the years to come.”
He said that he would remain as deputy leader until polling day in December and would be playing an “active part” in Labour’s election campaign.
Mr Watson was elected to the position in 2015, at the same time as Jeremy Corbyn was elected Labour leader.
During their time together at the top of the party the two men clashed repeatedly, with Mr Watson, a former ally of Gordon Brown, becoming a focus for the “moderate” opposition in the party to Mr Corbyn.
After 35 years in full-time politics, I've decided to step down and will be campaigning to overcome the Tory-fuelled public health crisis. I'm as committed to Labour as ever. I will spend this election fighting for brilliant Labour candidates and a better future for our country. pic.twitter.com/qGqiKTJ6br
— Tom Watson (@tom_watson) November 6, 2019
He was publicly critical of the leadership’s attempts to tackle anti-Semitism in the party and led moves to push it into supporting a second referendum on the EU, despite the entrenched resistance of the leader.
Most recently, he defied Mr Corbyn by calling for the party to back a new public vote before the country went to the polls in a general election.
His opposition to Mr Corbyn angered allies of the Labour leader and on the eve of the Labour Party conference in September, they made an unsuccessful attempt to oust him by abolishing the post of deputy leader.
Despite their differences, Mr Corbyn said he was “proud and glad” to have worked with him over the past four years.
In his reply to Mr Watson, he wrote: “Few people have given as much to the Labour movement as you have and I know that many thousands of members and trade unionists that you have inspired and worked with over the years will be very sorry to see you go.”
In recent months he has faced intense criticism over his role in promoting the false claims of a Westminster paedophile ring made by the fantasist Carl Beech.
Thank you @tom_watson for your service to our party and your constituents. I know you’ll continue to take on the vested interests of the Murdoch empire, big sugar companies and the gambling industry. This is not the end of our work together. pic.twitter.com/MpYLVklHdr
— Jeremy Corbyn (@jeremycorbyn) November 6, 2019
Beech’s allegations led to a number of public figures coming under police investigation, including the former home secretary, the late Lord Brittan of Spennithorne, the former head of the armed forces, Lord Bramall, and ex-Tory MP Harvey Proctor.
After facing calls to resign by some of those involved, he said that he was “very, very sorry” for the way events had turned out, but stopped short of apologising.
Mr Proctor said on Wednesday that he had done his constituents a “great favour” by standing down.
“The next parliament will be a healthier place without him,” he told the PA news agency.
Mr Watson, who first entered Parliament in 2001, has also spoken openly about his struggles with his health.
Last year he disclosed that he had been diagnosed with type-2 diabetes, but had managed to “reverse” the condition, losing seven stone in weight.
He said that he would be using his time outside Parliament “campaigning to overcome the Tory-fuelled public health crisis”.
He held his West Bromwich East seat with a 7,713 majority at the 2017 general election.