Yvette Cooper, Andy Burnham and Liz Kendall suffered defeat at the hands of Jeremy Corbyn in Labour's 2015 leadership election, effectively routing the party's modernisers. But the centrists seemed to have found a new faction head in the shape of former Army officer and Barnsley Central MP Dan Jarvis.

The Afghanistan and Iraq veteran outlined his vision of what Labour needs to do to win the 2020 general election during a speech to the Demos think-tank in London on 10 March. The former paratrooper argued New Labour failed to address people's concerns over mass migration and did not do enough to tackle inequality.

"New Labour didn't see with sufficient clarity the downsides of globalisation. They knew it meant cheap consumer goods. But, they didn't recognise that too often, it meant cheap labour too. Today the average income in Barnsley is still over £100 a week less than the average income in Barnes in London. I believe this gap matters. It's bad for our economy. It's bad for our communities," said Jarvis.

He also wants the next Labour government to be more economically radical than the Tony Blair and Gordon Brown years. "If we do not share the proceeds of growth fairly then the moral foundations of our economy are called into question. Put simply, Labour needs to be tough on inequality, tough on the causes of inequality," said Jarvis.

Corbyn's Praetorian Guard

The major address is expected to be seen as a leadership challenge against Corbyn, who has faced resistance from Labour moderates in the parliamentary party over his left-wing proposals.

The Labour leader most recently triggered a row over prostitution when he called for the decriminalisation of the sex industry in the UK.

Top Labour MPs such as shadow foreign secretary Hilary Benn have also openly opposed Corbyn's anti-Trident stance. But Jarvis stressed his speech was "no way seeking to be a critique of anyone in the Labour Party" and the father of three ruled out a leadership bid in the wake of Ed Miliband's resignation after the 2015 general election.

However, bookmakers Ladbrokes have slashed Jarvis' odds to succeed Corbyn, putting the former Army man favourite to become the next Labour leader at 4/1. Jarvis' speech comes as pro-Corbyn activists seek to sure up the left-winger's position at the top of the party.

Jeremy Corbyn CND rally 27 Feb 2016
Corbyn at a CND rally in London Paul Hackett/Reuters

The Labour leader has his own pressure group in the shape of the 60,000 strong Momentum and the Public and Commercial Services Union also plans to form its own pro-Corbyn group (Trade Union Momentum) with the Fire Brigades Union.

A parliamentary party plan to topple Corbyn could also come unstuck because of his popularity among Labour members. The Islington MP won the party's leadership election with a staggering 60% of the vote, while Andy Burnham came second with just 19%.

A spokesperson for Corbyn had not responded to a request for comment from IBTimes UK at the time of publication.