Conservative MPs looked over the precipice and some of them stepped back. But not enough to prevent an unruly confrontation over the twin issues of immigration and Europe that could, as their one-time leader Michael Howard angrily warned, cost them the election next year. And not enough to escape the impression of a prime minister who is losing control of his party. Despite a handful of high-profile retractions – the leading rightwinger Douglas Carswell was among those returning to the fold – Dominic Raab’s amendment giving ministers power to deport convicted criminals without an appeal to the right to family life was supported by 97 MPs, 85 of them Tories. The government, which abstained, was saved from humiliation only when Labour chose to vote against the amendment.

For the rebels, their defeat had many of the attributes of victory. David Cameron is left looking weaker than ever, less able to handle the next confrontation over Europe whenever it comes. Labour and the Liberal Democrats, who voted together against the Raab amendment, have established a further piece of common ground.

The Commons debate was a deeply political occasion, a matter of last-minute deals, hand-written amendments and low horsetrading. Not an attractive sight for voters who, an Ipsos Mori poll showed earlier in the week, now regard immigration as the most serious issue facing the country. This may not be surprising, in the context of the sometimes grotesque misrepresentation of the nature of immigration and the hysterical anticipation at the start of the month about the arrival of Romanian and Bulgarian citizens in much of the media.

But it is also true that there have been good reasons recently for the public to question the government’s capacity to monitor and control migration – although it is worth noting that the British Social Attitudes survey found as long ago as 1995 that two-thirds of voters thought immigration was too high. Net migration at that time was a mere 60,000, easily within Mr Cameron’s new objective of a “sensible” level. In those days many Conservatives were enthusiastic advocates of extending the EU to the Baltic in the north and the Black Sea in the south. They were equally passionate about the free movement of capital and labour. This week, many of the same people will have been voting against the consequences of their actions. Immigration and Europe are now, for all political purposes, aspects of the same problem – and a colossal party management headache for the prime minister.

The government is visibly shaken, and no wonder. The bill – a largely mean-minded and probably not very effective attempt to clamp down on illegal migrants and make deportations easier – has had a wretched passage. Debate had to be postponed before Christmas in order to prevent MPs from voting on an amendment attempting to extend restrictions on Romanians and Bulgarians before the restrictions ended on 1 January. But that did nothing to prevent the sense of crisis mounting as about 95 MPs signed a letter demanding a move to extend restrictions on Romanian and Bulgarian workers. More than 100 backed the Raab amendment before the vote, including former Labour home office ministers

At the eleventh hour, Theresa May introduced another amendment proposing powers to strip Britons born abroad of their citizenship, leaving them stateless, a power more customarily reserved for dictators. Mrs May insisted it would be needed only rarely and the Lib Dem leadership backed her, even though, as the former DPP and now Lib Dem peer Ken Macdonald observed, it would unquestionably be fought to the bitter end in the courts. When there are already signs that the existing power to strip citizenship from those with dual nationality is being used more widely, this looks like another disproportionate move in the name of security. It was a bad day for Mr Cameron, and it will not have done much to reassure those worried about migration.