Labour is facing an existential crisis, key Corbyn supporter MP Clive Lewis warns

The shadow defence secretary said Labour could lose votes to the left, right, and centre

Clive Lewis MP says he is prepared to flout Labour's three-line whip (Rex)

Labour faces an “existential crisis” and risks losing ground across the country to opponents on the left, right and centre, one of Jeremy Corbyn’s key supporters in the Parliamentary Labour Party has said.

Clive Lewis argued that the ongoing civil war within Labour went deeper than either personality or short-term political positioning and that it reflected a longer-term malaise for the party.

The shadow defence secretary argued that a “managerialist” Labour party had already lost ground to parties with a coherent “vision” – such as Ukip, the SNP, and the Greens.

“The current crisis within the parliamentary Labour party is not some silly ego-led squabble between wannabe leaders. It is the expression of a much deeper crisis within the Labour party and its relationship with its voters,” he argued.

“Nor is it a question of repositioning the Labour party on a simplistic left-right axis – needing to move to the right, or the centre. And just in case you think I’m being partisan, it isn’t just a case of moving to the left either.

“The fact is whichever way we move now we’re going to alienate some key parts of our potential electorate.”

Mr Lewis made his diagnosis in a speech at a cross-party event this week organised by the think-tank Compass. He argued that where people had felt abandoned by Labour, forces such as Ukip and Vote Leave had been ready to step in to fill the gap.

Clive Lewis has remained loyal to Jeremy Corbyn (Sky)

“In May 2015 we lost votes to the SNP, to Ukip, and to the Greens – three parties with wildly varying positions on the left-right axis. We failed to win over Tory-Labour swing voters, we failed to get anywhere near enough Lib Dems, who should have been flocking to us,” he said.

“This means the Labour party is fighting for its survival on several different flanks at once. Politically that’s a very dangerous place to be. Now we have this referendum result which confirms what May 2015 told us about where many working class voters were going. They feel abandoned by the Labour party and now in their turn they have abandoned the Labour party in growing numbers.”

The MP, who has remained loyal to Mr Corbyn despite a spate of resignations, warned that Labour’s destruction in its former Scottish heartland could be mirrored in Wales.

“There was something laughable about Ukip until very recently. Leave the EU? Don’t be silly. Now, here we are. There was something laughable about SNP activists doorstepping a Glasgow council estate 20 years ago. Scottish independence? Don’t be silly. Now here we are, it looks more likely with each year that passes,” he said.

“Maybe there isn’t something so very laughable about Plaid Cymru’s dream about an independent Wales now. Who knows what’s happening deep in Welsh hearts.

“One thing is for sure – Plaid Cymru aren’t going to sweep to victory from targeted focus groups in key marginals. It has been a vision that has kept them alive and if they ever win power it’ll be that same vision that takes them there.”

The shadow cabinet member, a former soldier who fought in Afghanistan, suggested that Labour stop “bogus” listening exercises to give the impression of reconnecting with lost voters and instead embrace democracy wholeheartedly – including proportional representation.

“We might have got some working group that reported to the leader’s office, that sort of thing. A couple of paragraphs on page eight of the Guardian,” he said.

“One of the ways is to stop all the bogus listening and actually give people the power to speak.”

Mr Lewis added that he would not “rubbish” those who had criticised Mr Corbyn, arguing that there had “been quite enough of that already”.

“Whatever happens within the PLP over the coming weeks the great majority of us are going to have to work together again whatever format that takes."

A move by rebels within the Labour party to oust Mr Corbyn has stalled in recent days as no candidate has yet put themselves forward to challenge him. Mr Corbyn has said he will not resign.