The relationship between a Prime Minister and a Home Secretary is different from that between a Prime Minister and, say, a Communities Secretary.  To put it plainly, Theresa May can ultimately impose a view on James Brokenshire, as she could on Sajid Javid when he held the post.  As could David Cameron on Greg Clark, Gordon Brown on John Denham, Tony Blair on David Miliband – and so on.

But Prime Ministers have less room for manoeuvre with the holders of the great offices of state.  Certainly, they have the power ultimately to reshuffle or sack them.  None the less, David Cameron treated May with circumspection – as Tony Blair did Jack Straw and David Blunkett.

Only when Prime Ministers are exceptionally strong or weak does the power balance of the relationship swing one way or the other.  May herself offers examples both ways.  May Mark One, before the 2017 general election, was in a strong position despite commanding only a small majority, and was of course a former Home Secretary herself.

She thus dominated Amber Rudd.  May Mark Two, after the disaster of June 2017 and the loss of that majority, was suddenly in a weak one.  And she needed Javid after Rudd’s resignation over the Windrush fiasco – or felt she needed him, at any rate, which in practice yields much the same consequences.

Furthermore, Cabinet discipline has now broken down completely.  Some Ministers now brief journalists before meetings about what they will say about Brexit rather than simply leak details afterwards.  One experienced hand describes Cabinet as a “political Mogadishu” – with rogue Ministers, imaginarily clad in shades and ammo belts, firing rounds off into the air in the manner of Black Hawk Down.

This is the context in which to view Javid’s breaks for new ground on matters as diverse as Windrush, cannabis oil, police funding – and immigration.  He has torn up the “tens of thousands” net target.  Downing Street keeps up a rearguard action, but it has lost the battle: the target is not in Javid’s White Paper (though it was in the Conservative Manifesto).

We are unlikely to know what will fully emerge from that paper for quite some time.  Ministers’ disagreements about key policy decisions will stretch, in the event of a deal, into the transition period during the years ahead: for example, we are unlikely to know about salary thresholds for migrants until 2020.

If the background to those clashes is declining public concern about migration, the essence of them concerns business – or, rather, bigger business.  On the one hand, some Ministers, especially those in the economic departments, want a business-driven policy based on the economic model prevalent since Labour took the lid off the previous system of immigration control.

Philip Hammond and Greg Clark are both in that camp, reflecting the institutional interests of their department.  On the other hand, there is a weakened Prime Minister, whose instincts were shaped by her Home Office experience.  She is being forced to retreat – apologising for a reference to EU immigrants “jumping the queue” when she might formerly have toughed it out.

Where does Javid stand?  A lot is read either way into his background as the son of a migrant from Pakistan – rather speculatively in our view – but it might make more sense to look at his life story in the round.  He was a high-achieving banker and that working experience reinforced his belief that the capitalist system works (for all its faults and flaws).

The Home Secretary has learned the tricks of the political trade very fast, but the broad outline of the White Paper suggests that his approach leans towards that of the bigger business lobbies.  Some of the decisions look sensible.  If there is to be no cap on high-skilled migration from outside the EU, it makes no sense to have one on migration from it, in the event of a Brexit deal.

Similarly, it might make sense to extend the Youth Mobility Scheme in place for some countries to the EU27 on a reciprocal basis.  But the fundamental question is how high-skilled work is to be defined.  Graduate level is one thing. A level is another, as is NVQ.  And, as we say, the salary threshold level is still being debated.

Opening up a route for unskilled workers from “low risk” countries looks more questionable – and an attempt to get round the way in which immigration figures are compiled.  So do proposals to drop requirements on employers to advertise jobs in Britain before recruiting from overseas.

Javid is reported to want to cut EU migration levels by 80 per cent, but it is unclear how this will happen, given the indecision about salary levels.  The bottom line is that while public attitudes “have softened in recent years”…”British views are not favourable towards immigration and a substantial majority would like immigration to be reduced”, according to the Migration Observatory.

Polling by Lord Ashcroft found that this view was the second-biggest driver of the EU referendum vote.  The belief that the UK will now “take back control” appears to be driving the softening of attitudes we describe.  Furthermore, EU net migration has fallen since 2016 – though claims by Remainer diehards of a “Brexodus” are unfounded: more EU citizens are still entering the UK than leaving.

Meanwhile, non-EU migration is running at the highest level for 14 years.  There is thus no reason to be sure that the pendulum of public opinion, having swung one way, may not swing another.  Javid is right to ditch the net target: it has never made sense to have a policy half-based on a factor one can’t control – outflow.

But the essence of a post-Brexit migration policy should be roughly that set out by Iain Duncan Smith on this site in the aftermath of the referendum: work permits, a cap, and arrangements whereby “people allowed in to work should have to have a record of contributions over a period of time before being able to claim support from the state”.

The UK economic model since at least the New Labour years has been based on London-centred growth, financial services, higher migration and downward pressure on wages.  If the referendum result outside the capital was a vote against anything, it was a vote against that.

In short, immigration policy isn’t just the business of business.  It’s the business of everyone.  Weaning firms off the immigration settlement it’s been used to since the mid-2000s will take time, and depend to some degree on the short-term needs of the Brexit economy.  But the long-term trajectory should be clear – lower inflows.  Javid must show a clear pathway to them.