It was Corbynism and the mass movements that have shaped British politics more than the commentariat care to admit

Political crises arise in those rare moments when a spotlight is turned on the establishment, revealing all of a sudden the grimy reality of government policies and motives that their media and establishment flunkies usually do such a good job of hiding.

The crisis of George Osborne (triggered by IDS, not the IDS crisis) has all the characteristics of a typical political crisis: whether it knows it or not, it is usually the movement – those opposing the government through argument and action – that is responsible for turning the spotlight. Other faultlines are usually revealed, beyond the initial trigger for the crisis, and the establishment – not just the government – will do all it can to return to normal. The degree of success it has in doing so will be in inverse proportion to the level of change triggered by the crisis. It is the duty of the movement to keep the spotlight shining and to remember, and serve as a reminder of, what it has revealed.

This time, we will argue, the crisis would not have happened if Corbyn were not the leader of the Labour Party. Further, it has exposed some truths about Corbyn's opponents: that they hate him not because he can't win but because he might; not because he is an ineffective opposition leader but because he opposes the “extreme centre”. And they will do all they can to help Osborne regain his footing. We will argue that if we want to keep the spotlight shining we have to focus on the enemy, on Osborne and Cameron, not Iain Duncan Smith, on austerity, not euroscepticism.

Corbynism moves IDS's conscience

Without Corbyn this would not have happened, or, at least, would not have been a crisis. First, we must remember, and cannot repeat often enough, that the majority of Labour MPs did not vote against the welfare cap decrease last summer. In fact, not one of Corbyn's rival leadership candidates opposed it.

One MP, Angela Smith, said this week “If Corbyn is not prepared to buckle down and show proper leadership he should just go, and give us a chance to get a leader who can properly take on the Tories.” Proper leadership means defending the weak, the poor, the disabled against vicious cuts. Not backing the cuts and then giving sound bites about Tory infighting.

Imagine an alternative future, one where Liz Kendall and shadow chancellor Chuka Umuna had been calling for Osborne to do better at cutting the deficit, supporting him in kicking disabled people in the teeth, in the name of "aspiration". How could they have capitalised on this crisis? Cameron would have ripped them to shreds, reminding them of their own voting record and their role in previous Labour governments which got the country in the mess in the first place. That is, if they were not cheering him on from the dispatch box or telling him he could have cut benefits better.

In a more general sense, too, it was the movement that swept Corbyn to victory that kept up the pressure on Osborne and IDS. It is no coincidence that one of the strongest most vocal constituents of the People's Assembly against Austerity has been the disability activists. It was the revulsion at the 184 MPs refusing to oppose the welfare cap that helped cement Corbyn's lead last year.

Immediately after the budget, the media, from the Guardian rightward, started lauding Osborne as one of the great chancellors of the modern era, a genius statesman who, through sheer mastery of spin, could kick the poor while occupying the centre ground. Only, the movement wouldn't forget that this was a nasty party with a nasty budget willing to cut benefits for the most vulnerable while graciously granting tax breaks to their millionaire pals. Corbyn amplified this. Finally Duncan Smith admitted it. His resignation, throwing the Tories into disarray, is a victory for our movement and would not have been achieved through Blairite triangulation and Brownite moderation.

Kamikaze Blairites strike again

The Blairites know this. That's why they turned up the volume this week, demonstrating once again that their level of vitriol against Corbyn is in proportion to how well he is doing, not how badly.

John Woodcock, increasingly reminiscent of the Army Major riding a Trident missile in the final scene of Dr Strangelove, chose this week, the week the Tories spun into crisis and two polls put Labour in the lead, to say Jeremy must go. Yvette Cooper released her own statement about the budget highlighting, above all else, that Osborne will miss his welfare reduction targets (maybe she wants to have a go at cutting herself, if only she could convince Rupert Murdoch she would make a better technocrat and a more humble servant than George).

One of the more peculiar charges thrown at Corbyn is that he should have laid into Iain Duncan Smith rather than George Osborne. This tells us a lot about the Blairites.

For them the key point is not to oppose the policy and its executor Osborne but the image and the easier target IDS. It is not to focus on benefit cuts (which they do not really oppose anyway) but on the euro-infighting and IDS's euro scepticism. These strategic geniuses do not want to fight on the issue of deeply unpopular attacks on the disabled and fight to tar Osborne with the nasty party image he deserves; no, these electoral Jedi want to fight on the issue of Europe, where polls show working class labour supporters are split, and where they themselves agree with Cameron and Osborne. The truth is that they would pick Osborne over McDonnell every time.

The truth is that they are dedicated defenders of the “extreme centre”. Rather a government in the interests of the bankers and the rich than a labour government that restrains the "free market". For them, nationalisation of the railways, energy companies and banks, and strategic government investment in lifting high-tech, green industries and creating jobs, as well as expanding welfare, stands against everything Labour governments did since 1997.

We call them “kamikaze Blairites” because, though they might have entered politics as careerists, they are leaving it as martyrs for the cause of nuclear weapons and financialised capitalism. Willing to destroy Labour – hoping to destroy Labour – in the name of mammon (though the sacrifice is not so huge when 70 directorships await in politicians' heaven).

Osborne's defeat points the way to our victory

Within days the spin of a master statesman's budget had given way to the crisis of the Conservatives. The routine hard work of denouncing Tory policy on the basis of ideology rather than political point scoring had paid off. The years of meetings and hours of leafleting had paid off. The attacks on disabled people had been reversed.

This is how we can win. The past week shows there is more to politics than presentation. Corbyn and Sanders show that there is more to popularity than dinner with Murdoch. The stronger the movement against war and austerity, the stronger Corbyn will grow.

Where we focus our attacks on the “extreme centre” and their core politics of impoverishment we will do better than well-spun press releases about euro infighting. And where the movement is strong enough to outweigh the labour right, their sniping and nit-picking will become irrelevant.

There are two wrong ways to support Corbyn and one right way. We will not win by compromise, moderation and spin. Corbyn is not slick enough, his policies not palatable enough for the establishment, for this to stand a chance. We will not win by machinations within Labour, campaigns for deselection and other bureaucratic procedures - the mass of ordinary people do not see the Tories as the nasty party simply because a motion said so. Both wrong ways have in common that they forget how we got here: by building a movement, by giving voice to people's anger.

The right way to help Corbyn was on display this week. Build a campaign, as big and as loud as possible, in every forum we can, to take on Tory policies. That is why Osborne's hopes of becoming Tory leader are in tatters. That is why it is so important that the People's Assembly against Austerity has made "Osborne must go" one of its key demands for the demonstration on 16 April.

The labour movement can push back Tory cuts from where it is best placed to do so: in the workplaces and communities, in the streets and through every public channel where its voice is heard. The junior doctors’ strike, student rent strikes in London, mass marches organised by Stop the War, CND and the People’s Assembly, and the success of alternative news outlets like Counterfire’s new broadsheet show that the mass of the people want a socialist alternative to austerity. And they are only a snapshot of what is possible – if Corbyn is not left alone to fight the Tories in Parliament.