Coup attempts. Unexpected resignations. Nominations and betrayals. Today’s political landscape is bloodier than the most plot-packed episode of Game of Thrones, and certainly moving at a comparable pace. Unlike the cult TV drama, however, we’ve got a leadership figure with an enormous mandate who has been consistently honest, forthright and dependable. Here is a parliamentary personality with unimpeachable commitment to his values, to politics and to people.

Jeremy Corbyn is the leader his party wants and the one our country, deeply riven by the Tories’ failed austerity experiment, needs. So why are we so determined to waste this opportunity? Corbyn offers the left an unassailable narrative. It has already captured the Labour membership’s imagination, with numbers having more than doubled since Corbyn took the reins and growing daily. More than 60,000 people have joined Labour in the week since the referendum, many buying, it seems (and in a very real sense) into the committed alternative he offers. Corbyn himself isn’t all that great as an orator, but he’s steadfast and resolute, he embodies a viable, believable and highly electable opposition to the careerist establishment figures we have come to reject. True, just nine months in, the movement behind Corbyn hasn’t yet had the reach it both requires and deserves. But this is surely due to the fact it’s been deliberately beset by a thoroughly hostile mainstream media and a host of unconvinced MPs.

The Parliamentary Labour party (PLP) faces the impending Chilcot report and spiralling distrust of windsock politicians brought on by the deceit of the EU referendum campaigns. The elixir of “electability” should matter to it less than meaningful representation. Sacrificing honesty and principle for presentation doesn’t just undermine public faith in democracy, it also robs the people you represent of their voice. Struggling to pluck from their ranks a challenger who didn’t vote for the Iraq war, the PLP’s botched coup serves only to emphasise that Labour needs a solid, unflinching case for itself. The movement behind Corbyn, with his grassroots and ever-growing backing, remains that case.

We are truly down the rabbit hole when a mandate such as Corbyn’s, the largest of any party leader ever, accounts for nothing. Carving pledges into a risible tablet doesn’t work. Austerity with insincere socialist window dressing doesn’t work. Trying to out-Tory the Tories doesn’t work. Corbyn has won four out of four byelections, we now have a Labour mayor in Salford, Liverpool, London and Bristol. He commands widespread and robust trade union support, and on the EU referendum, only 1% fewer Labour members voted to remain than among the SNP. Despite the internal campaign against him since he got on the ballot, Corbyn is doing well.

How much better could we, as a party and as a movement, be doing if we’d thrown our coherent weight behind unity from the start of his tenure? Every day, a new borehole into Corbyn’s leadership has been drilled by the PLP, its supporting media and its opposition taking polite turns with the knife in their cosily mutual attempts to gut the movement.

As would-be leadership candidate Angela Eagle said herself just three weeks back: “Jeremy is up and down the country, pursuing an agenda that would make a 25-year-old tired. He has not stopped. We are doing our best, but if we are not reported it is difficult.”

If the PLP insists on refusing to respect the membership and the elected leader, it should be them, not Corbyn, that lose their jobs. If he were to stand down now, it would serve only to vindicate the smears, the plotting, the patronising and the deliberate blocking of democracy. The party would haemorrhage the movement that’s been building.

There is no viable alternative leader ready to take up the mantle and, even if there were, they would make little difference to Labour’s fortunes if a snap election were called at this point, because of the damage the PLP has done to the party’s credibility. This undemocratic self-sabotage, coming from a group that purports to believe passionately in social progress and the Labour movement, is incomprehensible.

Many Corbyn supporters do respect the establishment of the PLP. We care that 172 of our MPs, trusted, elected, dedicated, are telling us “no”. Each resignation, each laden speech, shakes us to the core. Already in turmoil from the referendum result, it takes concerted effort, buoyed up by the strength of an unstinting movement, to plough on resolutely. . Corbyn’s Labour commands this much loyalty and passion – and a united party spreading his reach without wavering would take that ever further. To the two-thirds of Lib Dem voters who slipped off the radar in the face of coalition. To the 34% of disenfranchised electorate who didn’t vote at the last general election. To those who have turned to Ukip in the eager hunt for a genuine alternative. We can be that alternative.

It would be wrong to label my stance, shared by hundreds of thousands and counting, a fringe position. Amid the turbulence – the coups and the culls and the knives in backs – there’s one thing that remains constant – it’s Corbyn. He may never roar, because he’ll never do anything that isn’t authentically him – that’s his pull, his USP, his brilliantly electable quality. So we need to get behind him fully, MPs and all: because with both a team of dedicated MPs and a passionate grassroots movement behind him to roar, his soft and steady tones will be quite loud enough.

Lucy Whitehouse is a young Labour party member and activist