Senior Tories from across the party are warning that Rishi Sunak’s emergency Rwanda plan will never become law in its current form, ahead of the most critical vote of his premiership. Liberal Tories confirmed last night that, despite their desire to back the PM against the right, “serious concerns” remain about the plan and more reassurances will be required. Meanwhile, a self-styled “star chamber” of legal figures examining the proposals for the Tory right is understood to have found problems that are “extremely difficult to resolve”. It means that, despite Tory whips believing they will have enough support to win the first vote over the proposals on Tuesday, there is nervousness among moderate Tories that Sunak is set on a course that has united his opponents and will ultimately imperil his leadership. “This is a bit like Brexit in the sense that it will have the effect of drawing the whole of the right together,” one influential figure on the right said. “It is the uniting of the right.” A former minister added: “In six months’ time, if we find that the bill is law but it hasn’t worked, then that’s going to be catastrophic for Rishi. So they better make it work. The stakes couldn’t be higher.” The first major vote on the Rwanda bill, which is designed to ensure that migrants coming to the UK in small boats can be deported to the country without being blocked by legal challenges, is set to take place on Tuesday. However, concerns within both the liberal and rightwing groupings of the party appeared to be hardening against the proposals this weekend. While the right believes the plan does not go far enough in disregarding the European court of human rights, the left now has several concerns this weekend, including that it contradicts international law. Groups on both wings are set to meet onMonday to thrash out their positions. Writing for the Observer on Sunday, Damian Green, who is chair of the One Nation caucus of liberal Conservative MPs, said he wanted to believe the prime minister’s assertion that the proposals remain within the law. “That should not disguise the real concerns we have about the detailed proposals within the bill,” he writes. “The concerns we have fall into three sections. We are worried about legislation by assertion, in that the bill baldly states that Rwanda is safe. The government needs to show that this is the case. The bill also gives ministers powers without a chance of review, which also needs exploration. The third concern is the removal of the duty on public authorities not to breach human rights.” While it is likely there will be enough support to see the bill through its first vote on Tuesday, some MPs said that could not be taken for granted. A rebellion of only about 30 Tories is required to see it defeated. Senior legal figures are now also casting a dim judgment. Nick Vineall KC, chair of the Bar Council, said: “The bill raises some serious rule of law issues ... The bill deems Rwanda to be safe, whether or not it is in fact safe, but our obligation under international law is to ensure that asylum seekers are only ever sent to countries that are actually safe. The circumstances in which human rights challenges are permitted by the bill are extremely tightly constrained. There will inevitably be legal challenges.” Figures on the right said there were no immediate plans to submit letters of no confidence in Sunak, with everyone focused on examining the details of the Rwanda bill. However, many MPs now believe Sunak’s future is tied to the bill’s fate. Many are comparing his plight with that of Theresa May, brought down when she attempted to push through a compromise Brexit deal in the face of opposition from the right. Some MPs believe the party’s whips are simply desperate for the bill to pass on Tuesday, after which Sunak will blame Labour for blocking the Rwanda plan as part of his election pitch. Those suspicions appeared to be reflected in comments made by Sunak on Saturday night, when he said that Labour had “no plan to tackle illegal immigration”. He added: “This week, Labour needs for once to rise above political games. They need for once to stop acting in their short-term interests. They need to act in the national interest.” It comes as Keir Starmer attempts to capitalise on the Tory infighting with a speech appealing directly to those who switched to the Conservatives at the last election. Speaking from a target seat on Tuesday, he will also attempt to win back voters in the so-called red wall seats by saying his party embodies “British values” – and that Sunak’s ability to lead has collapsed. “While they’re all swanning around self-importantly, in their factions and their ‘star chambers’, fighting like rats in a sack, there’s a country out here that isn’t being governed,” he will say. “I have dragged this Labour party back to service, and I will do the same to British politics. I won’t let the Tories drag our country down with them.”