In some Labour circles, the decision to vote for Jeremy Corbyn is treated as a dereliction of duty, one of a ship’s captain watching gleefully on from shore as his vessel sinks and the thinktank Progress rushes out to save all the women and children.

Despite this portrayal of Corbynistas as reckless ideologues, and yes, despite a flurry of bad polls, it is clear to me why Corbyn and most importantly, his vision, must win.

Labour under Corbyn’s stewardship hasn’t been the catastrophe that many in the parliamentary Labour party wished it to be, no matter how hard they tried to make it so. Stopping the Tories and their myriad of welfare cuts during this parliament, or forcing the U-turn on a forced academisation programme is opposition worthy of the name.

It isn’t a Labour Government, but it is Corbyn and to a large part his shadow chancellor John McDonnell who have turned the Labour tanker around to face these issues head on.

Take a trip back to the weeks before Corbyn’s election. Harriet Harman was dancing on the pinhead of the welfare bill whilst Chris Leslie was an impotent shadow chancellor. At the very least, the meaningless managerialism of an ever-shifting centre ground is over. It appears to be dying right across Europe.

To understand the choices that lie before Labour in Smith vs Corbyn, we must also understand where the party stands. Last May’s disastrous defeat saw Labour politicians and pundits alike speak of the uphill task of winning power again. Labour had lost two elections on broadly moderate tickets and had begun losing millions of votes during the stints of Blair and Brown. At this point, Labour was a ship with no rudder, let alone a map to show it where to go. Andy Burnham, Yvette Cooper and Liz Kendall were sharing a soapbox and had their backs turned to the crowd.

It was Corbyn that successfully reclaimed Labour’s voice and begun reupholstering the party, from top to bottom. Turning a party around in the aftermath of an election that haemorrhaged votes nationwide takes time and support. Labour’s resounding victories in every Parliamentary by-election and mayoralties since were bitter pills to swallow for Corbyn’s enemies, inside and outside the PLP.

Undeterred, Jeremy Corbyn has continued to inspire thousands into becoming Labour members. It is now the largest party in Europe. Of course this is no arbiter of governing ability, but it is a mass resource that tapped into, can help the party reach into corners that others simply cannot.

Now, here is the important bit. Derailing this progress now - which is what removing Corbyn would do - would see the air in the chests of thousands of new members sucked out and their potential contributions curtailed. All that will be left would be a vacuum. And those who would fill it are those still wanting to walk down the middle of a road that has long since been diverted. The dynamic of politics as we know it is changing. The centre and centre-left across Europe is struggling. These parties are seen as the managers of crisis, complicit in the proliferation of today’s iniquities. In Britain, we have a country in flux where migrants and exploited workers may bear the brunt of a vicious Brexit. A Labour party led by Corbyn can unashamedly be the one to lead the response.

This is why the Labour leader cannot be Owen Smith. At a time when Labour needs to clearly stake its place, we cannot see a return to flip-flopping. Whether it be Iraq, privatisation of the NHS or workers’ rights, Smith appears to want to be everything to every man; to be a practical radical. But Smith, it seems, is just not trusted among many Labour members. To mobilise the Labour movement, first they must know that you believe what you say. At his launch, Smith eulogised about workers’ rights and ending the public sector pay freeze. Since, the Fire Brigades Union (FBU) pointed out that Smith supported a public sector pay freeze only last year. Inconsistency reigns, as do the gaffes.

Smith’s policy announcements are a direct result of Corbyn changing Labour’s offer to the membership and the country. Smith feels like the university student taking credit for a group presentation he had little to do with, an amateur actor reading a script he’s not seen before.

Labour under Corbyn can make progress, but he needs time, and the support from the PLP that he deserves. Not more, not less. Impatience from the likes of Neil Kinnock and those in the PLP tastes sour, especially coming from a man who lost two elections in nine years and a group of MPs whose monopoly on electability has seen Labour lose two elections in a row. Corbyn has had 10 months in a party that was in an existential tailspin.

Corbyn and his team have made mistakes, from inconsistent messaging and a lack of a comprehensive media strategy, to the failure to execute the simple task of proof reading a press release. But Corbyn’s messages do resonate, just as Ed Miliband’s strong interventionist policies polled well, with some later being stolen by Osborne.

The task now, should Corbyn win, is to take advantage of the lessons learnt and as the new Prime Minister distances herself from the idea of an early general election, bring the PLP together and go forward with purpose re-affirmed and renewed.