IT IS hard to imagine a more benign month for the Labour Party than the past four weeks. George Osborne’s budget quickly unravelled. Then Iain Duncan Smith, the welfare secretary, resigned and accused his party of looking after its rich supporters at the expense of the poor. Next came the news that swathes of Britain’s steel industry might have to shut. To top it off, David Cameron’s wavering response to the Panama papers, which exposed his family’s offshore holdings, put him on the back foot and reminded everyone what a privileged toff he is. All the while the Tories’ battles over Europe rumbled on. Who, in Britain’s opposition, could possibly have failed to profit from these blows?

Jeremy Corbyn, that’s who. Labour’s hard-left leader has honed a precise formula for such moments. First he launches or endorses a petition (in Corbyn-land, objecting to things is tantamount to changing them), which is duly signed by lots of people who already dislike Conservatives. This is typically accompanied by a wildly unrealistic call for a senior Tory to resign. That does not happen. Then comes the grand showdown in the House of Commons, at which—in a convention now so well established it should be written into Erskine May’s handbook on parliamentary practice—Mr Corbyn lets the prime minister off the hook, rattling off the case against the government with all the wit and agility of an automated supermarket checkout.

The coming weeks may prove just as damning. It is telling that Corbyn loyalists are trying to lower expectations before the local elections on May 5th. Getting their excuses in early, they warn that their candidate, Sadiq Khan, may lose the London mayoral race. Most revealingly, they are talking up a projection that the party will lose 150 seats at the elections taking place in towns like Milton Keynes, Gloucester and Rugby that decide national elections. As Marcus Roberts of YouGov, a polling firm, notes, the party should be aiming for around 300 gains. Any net loss of seats would be a “truly extraordinary event”, he adds.

Combined with Mr Corbyn’s absence from the Europe debate (as The Economist went to press Labour’s instinctively Eurosceptic leader was about to give a speech—at last—on the subject), all of this is nudging Labour legislators towards the “regicide” button. Some have already shown their colours, two calling for Mr Corbyn to go and Labour First, a group on Labour’s right, pushing for a change to the electoral rules that enabled him to win the leadership last autumn. If the party’s results in the local elections are bad, critics will initially hold their tongues and concentrate on the Europe debate. But already there is talk of public denunciation of Labour’s leader—and perhaps even a leadership challenge—on June 24th, the day after the referendum.

Other threats to Mr Corbyn’s leadership are less overt. Dan Jarvis, a much-fancied MP and former soldier, gave a leader-like speech on the party’s future on March 10th, while a “shadow shadow cabinet” of moderates offers the sort of incisive opposition from the backbenches that Mr Corbyn and his team fail to offer from the front. Local Labour branches are passing resolutions against anti-Semitism: a pointed objection to the spread of that virus since Mr Corbyn (whose criticism of Israel seems to be attracting all the wrong people) became leader.

Yet he is well dug in. In December he faced down his shadow cabinet over British air strikes in Syria. In January he fired Michael Dugher, a shadow minister who was critical of him, and clipped the wings of Hilary Benn, the shadow foreign secretary who had dared to speak out against his peacenikery. Tom Watson, his otherwise-rambunctious deputy, now seems cowed. Much of this betokens what Atul Hatwal, a Labour commentator, calls the victory of the “Stalinists” (cynical but capable fixers like Seumas Milne, Mr Corbyn’s Richelieu) over the “Trotskyists” (airy idealists like Jon Lansman, an ally of Labour’s leader who advocates bottom-up control of the party). In other words, Mr Corbyn’s operation has decided it needs to ditch the flowery stuff and nobble its enemies.

At the same time, Mr Corbyn is consolidating his grip on Labour’s membership, his last line of defence. Thousands of lefties joined last summer to vote for him. Many have been absorbed by Momentum, the party-within-a-party set up to defend Labour’s leader from the challenge he will eventually face. Without a drastic influx of moderate members and supporters, Mr Corbyn or his designated heir will win any new leadership election.

Breaking out of the bunker

So he is holding his ground. But that is not the same as going over the top: initiating the great battle, yet to be fought, over the soul and mission of the Labour Party. It looks as if the coming debate over the renewal of Trident, Britain’s nuclear deterrent, will prove to be that moment. Whenever he has the chance, Mr Corbyn talks about the case for unilateralism. Labour insiders suggest that he plans to go over the heads of his (mostly pro-Trident) MPs by holding a vote of party members and supporters and then taking the (probably anti-Trident) result as his position. Eager to foment discord, Mr Cameron seems willing to oblige, planning a vote on renewal for the weeks following the EU referendum.

All that might just be a dry run for a bigger confrontation: a new leadership election triggered not by the moderates (who are many months off feeling ready to take on Mr Corbyn and his thousands of idealistic supporters) but by the Labour leader himself. He is almost 67. Rumours swirl about his health. Supporters and critics alike suggest that he could step down, perhaps in 2018, and make way for John McDonnell, his shadow chancellor. Mr McDonnell is a decent media performer with vast ambitions and close links to Momentum; he is popular among the grassroots and has been touring Labour branches seeking their support. In other words: Mr Corbyn may be hapless, but Corbynism is not going to disappear. Mr Cameron is luckier than he looks today.

Economist.com/blogs/bagehot