At last week’s Spectator Parliamentarian Awards, Suella Braverman was awarded ‘Disruptor of the Year’. In her speech, which seemed to preview her Commons statement on Wednesday, the former home secretary joked that the prize ought, instead, to go to the man responsible ‘for disrupting my plans to cut the [immigration] numbers and deliver our manifesto pledge – the Prime Minister’. Rishi Sunak’s assembled supporters didn’t laugh.

On the issue of migration, battle lines have been drawn between the Tory tribes. The night before Braverman’s speech to the Commons, a trio of right-wing groups assembled to plot their strategy. Members were drawn from the European Research Group, the Common Sense Group and the New Conservatives. Around the same time, the reinvigorated One Nation caucus fired off a statement signalling their opposition to anything that would undermine Britain’s international obligations.

So far, Sunak has failed to stop the boats – despite it being one of his key promises

Opinions differ as to the strength of each faction. One moderate questions why Sunak spends so much time ‘listening to 15 New Conservatives and not 106 One Nation members’. But a right-wing rival compares the One Nation caucus to an onion, suggesting its layers can be peeled off with enough pressure. The jibing belies the seriousness of the issue: among 2019 Tory voters, immigration and asylum is currently the number one issue by 11 points. It even trumps concerns over the state of the economy, according to YouGov polling. The reasons are twofold: the constant stream of small boats crossing the Channel and the record net migration figures of 745,000 last year.

Net migration might have been less of an issue had the Tories had much to say on illegal migration. But so far, Sunak has failed to stop the boats – despite it being one of his key promises at the beginning of the year. The numbers are down on last year, but the overall impression is that the Tories have not dealt with the problem.

The Supreme Court’s evisceration of the Rwanda scheme last month has further frustrated Sunak’s plans. More than 63,000 migrants have crossed the Channel since the original first flight carrying asylum seekers was due to depart last June. After two previous legislative efforts, Tory hopes rely on an ‘emergency’ initiative to fix the policy before next year’s election. ‘It’s three strikes and you’re out,’ remarks one MP, who has argued for the strongest possible bill.

The current debate centres on whether Britain needs to opt out of the European Convention on Human Rights (ECHR) when it comes to asylum cases. Supporters of Braverman have called for ‘notwithstanding clauses’ to allow ministers to ignore the Human Rights Act and the ECHR on this issue. Those pushing for the so-called ‘full fat’ option point to the range of legal routes they have already tried in order to reduce Channel crossings. One advocate rattles off the existing measures to deter small boats: targeting criminal gangs, innovative technology, fines for those hiring illegal migrants and months of engagement with European interior ministries. ‘And it’s still only down by a third,’ they conclude, in exasperation.

Even some Tory critics of Sunak accept that ‘he has gone further on this than any prime minister before him’ and admit ‘he has been dealt a pretty bad hand’. On this, as with much else, the Prime Minister has spent hours trying to strike a balancing act between disapplying sections of the Human Rights Act and instructing UK courts to ignore the ECHR on issues relating to asylum.

As for the number of legal immigrants, the government has started ‘unpicking’ the system that Boris Johnson – arguably Britain’s most pro-migrant premier – introduced in early 2020. Immigration minister Robert Jenrick has publicly described past decisions, such as the reduction in the salary threshold for skilled migrants to £25,600, as ‘naive’. Initial Home Office assessments certainly underrated the take-up of new schemes. It was forecast in 2020 that fewer than 10,000 migrants would arrive on health and social care visas; more than 100,000 did so last year. Under Johnson, there was also a greater enthusiasm to attach mobility offers to free-trade agreements as shown by the Australian deal and talks with India.

Labour has, perhaps wisely, largely refrained from putting forward its own migration proposals in recent weeks. David Cameron’s pledge to bring legal arrivals down to the ‘tens of thousands’ still weighs heavily on the Conservatives to this day; there is little desire on Labour’s part to repeat the experience by trumpeting a headline figure. There was some frustration last month when Darren Jones, the shadow chief secretary to the Treasury, said the party would seek to return net migration to normal levels, which he defined as around a ‘couple of hundred thousand a year’. As for small boats, Yvette Cooper has reiterated that she would scrap the Rwanda scheme and instead focus on the criminal gangs. ‘It’s not either/or,’ retaliates one government figure. ‘We are already doing that.’

If Sunak fails to resolve Tory tensions over his Rwanda legislation, then the fate of his flagship bill could be in the hands of the Labour whips. His own party’s discipline is fraying. On Monday night, almost 50 Conservative MPs defied the party whip on a series of votes. The row over the infected blood scandal grabbed the headlines as the government’s first Commons defeat. But 26 Tories also voted against the electric cars transition – more than twice as many as previously briefed.

Fundamental questions of conservatism are being raised. For some Tories, the ECHR represents a great European legacy project; others see it as a foreign court of which we know little. Liberal Leavers such as Johnson saw Brexit as the beginning of ‘global Britain’ while cultural conservatives hailed it as the end of the global elite. With the polls pointing towards defeat for the Tories next year, it may well be that these debates soon take place in opposition, rather than the corridors of power.