When in one breath the whips tell Conservative MPs that an amendment is illegal and in the next tell them not to oppose it, it’s scarcely surprising that those same MPs split three ways, that headlines about “chaos” follow – and that the business managers are duly blamed.  But the sober truth about yesterday’s Commons debacle is that it tells us little we didn’t know already.

We know that David Cameron has no automatic majority on matters his backbenchers feel strongly about – usually Europe, immigration and any combination of the two.  We know, too, that, faced with defeat, he will run away to live and fight another day (or run away again another day).  Since, on balance, backing off votes damages his authority less than losing them, he isn’t really at fault for that. We also know that Labour has its own divisions, that some in that party wanted Raab’s amendment to pass, thus placing the Home Office and its bill in an even more difficult position – and that Ed Miliband thus helped the Government out by voting the amendment down.  This showed a certain lack of killer instinct.  Then again, the Labour leader was probably more interested in cuddling up to Nick Clegg and the Liberal Democrats, who joined Miliband in the lobbies to defeat Raab’s plan and show their power.  That the heart of most Liberal Democrats is in a future coalition with Labour, rather than the present one with the Conservatives, is something, too, that we know well.

What is less well known, or at least less usually evident, is something else that yesterday’s shenanigans showed up – namely, the bristling tensions and suspicion that exist between Downing Street and the Home Office.  As today’s Times report says, Theresa May was telling MPs from the dispatch box that the Government hadn’t yet made up its mind on the amendment while Number 10 was announcing that it had, and that Tory MPs would be asked to abstain.

When Downing Street says one thing and the Home Office another, the whips can’t reasonably be blamed for the ensuing confusion.  What on earth was going on?  The origins of the answer lie in the latter’s weird handling of Raab and his proposal.  It is a strange but true fact that there has been no face-to-face meeting between the Esher and Walton MP and Home Office Ministers to discuss his proposals since Christmas.  He insisted yesterday that his plan was legal and workable; May counter-insisted that the opposite is true.  Since the two are colleagues, one would have thought that either she or Mark Harper, the Immigration Minister, would have sat down with Raab to try to hammer out their differences.  Instead, the Home Office tabled a late blizzard of amendments, thus hoping that Raab’s one wouldn’t be called.  This was no way to run a railroad.  May and Raab have clashed before – over men, work and feminism.  It rather looks as though she was determined to freeze out the Esher and Walton MP and his plan.

This bloody-mindedness doesn’t reflect well on the Home Secretary.  None the less, what was a source of weakness in this case is usually a source of strength.  May’s determination to do things her way has made her one of the most successful Ministers in this government.  Non EU-immigration is down.  So is recorded crime.  Police reform is happening, without mass marches and protests.

Little wonder that the Home Secretary has marched steadily up the league table of future Party leaders in our monthly poll, topping it for the first time last month.  (This month’s survey results will be published next week.)  She makes little secret that she will stand for the leadership if the next election is lost and Cameron resigns, having set out her policy stall at ConservativeHome’s spring conference last year.  Like Michael Gove at Education or Eric Pickles at CLG, May has built a strong special adviser and civil service team around her at the Home Office, which is devoted to pursuing the Department’s political aims.  She is now a politician of the first rank and her potential candidacy should be taken very seriously.  All in all, it’s no wonder that Downing Street is reflexively suspicious.  These tensions are bound to be exacerbated when it seizes control of a bill, as it did in the case of May’s immigration proposals, delaying the measure before Christmas and bringing it back this week – with yesterday’s results.

The moral of the story is that when there are tensions between the Prime Minister and one of his most senior Ministers, one ends up with Number 10 briefing one thing while the Home Secretary is saying another.  We haven’t heard the last of these – and, in the meantime, it looks as though the only Tory winner from yesterday was the man who lost: Raab himself.