In an unprecedented step, the deputy leader of the UK's main opposition party has resigned on the first day election campaigning officially commenced. Tom Watson, deputy leader of the Labour Party, made the announcement on Wednesday evening. The move has overshadowed the announcement on Thursday by Labour’s economy spokesman John McDonnell to pledge £150 billion pounds of funding over five years to transform state education. Labour’s business spokeswoman Rebecca Long-Bailey described Mr Watson as “a force of nature’’ and said his departure would leave “a big hole’’ in the party. His resignation followed a dramatic start to the election built up which saw the leading Conservatives also face two major resignations. But the timing of Mr Watson's departure will be a major blow to leader Jeremy Corbyn and add to his party's woes. It comes as both the Conservatives and the Brexit Party are fiercely targeting traditional Labour heartlands in the north of the UK in a bid to woo Brexit voters disillusioned by their party's stance on remaining in the EU. Despite Mr Watson citing "personal, not political" reasons for his decision it will focus the spotlight on the party's internal feuding and comes just months after an attempt by party members to oust him on the eve of the party's conference. In a tweet announcing his decision, Mr Watson said: "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." He will remain in office until the December 12 election. The Labour Party has faced further misery as one of its former MPs Ian Austin urged “decent patriotic Labour voters” to back prime minister Boris Johnson. Mr Austin, once a senior adviser to former prime minister Gordon Brown and a member of the party for 34 years, said he would not be standing for Parliament. He left the party in February, citing Mr Corbyn’s failure to tackle antisemitism in the party and had been sitting as independent in the House of Commons. He said Mr Corbyn has spent his life siding with extremists and should not be trusted with power. “I tell decent patriotic Labour voters that they should be voting for Boris Johnson, I can’t believe it’s come to this,” Mr Austin told BBC Radio. “I regard myself as proper, decent, traditional Labour. I just think Jeremy Corbyn’s not fit to run the country.” Ms Long-Bailey told the BBC his comments were “absolutely absurd’ and said if people want to protect their communities, they should back Labour. However, on Tuesday former Labour defence secretary Lord Hutton of Furness told <em>The Times </em>that a Corbyn premiership would make Britain less safe and that Mr Corbyn was "unfit" for high office. He wrote: "Mr Corbyn is on record as saying that he would not use nuclear weapons, thus rendering the threat of Britain’s Trident missiles useless as a deterrent. But also, more perversely, that Nato was “set up to promote a Cold War with the Soviet Union”. "This is nonsense. Nato has for 70 years kept peace in Europe by being a voluntary security alliance. A Corbyn government would undermine that alliance not through mere obtuseness but out of the conviction that Nato is a threat to peace. It is a fantastical, calumnious notion of a politician who is unfit for high office."