Yesterday saw a spate of articles about the government’s immigration van pilot scheme. And today the Public Administration Select Committee (PASC) damns immigration figures as a ‘blunt instrument’ and not ‘fit for purpose’. The nub of the problem is that the methodology is outdated, having been designed in a time when migration was in the 10,000s a year rather than the 100,000s. A sample size of 5,000 identified through the International Passenger Survey, which is drawn from UK ports and airports, is not sufficiently broad to construct accurate estimates. New methodology is required, PASC says. You can read the whole thing here.

This will – and should – raise further questions about border control, although the Home Office has moved to pre-empt such discussion by rejecting PASC’s assumptions.  However, the figures have re-opened the government’s efforts to reduce net migration. This is one of the Home Office’s success stories – and it has been cautiously welcomed by Sir Andrew Green of Migration Watch, who is not easily pleased. Mark Wallace at ConservativeHome, though, is less charitable. He says that PASC’s figures have proved him right: immigration figures are based on little more than guesswork. He adds, portentously, that if ‘real doubt can be cast on those claims then it would be politically disastrous’ in 2015. He goes on to mention uncontrolled EU migration and illegal immigration – the whole shebang.

His analysis is predicated on the view that high levels of immigration (or in the case of the EU, open labour markets) are necessarily destructive. The Tory leadership plainly shares that analysis to an extent or else it wouldn’t be trying to reduce net migration. There is, however, another view. Vince Cable has been all over the airwaves this morning denigrating the Tories for ‘obsessing about this net immigration figure.’ Ergo, immigration/open labour markets are good for the economy. He can call on the support of all manner of political and economic institutions.

Guns to the right of him, guns to the left of him – can David Cameron actually win the immigration argument when every success is undone by allegations of failure? He’s lucky, though, that Theresa May is one of his most effective and ambitious ministers, and she cannot surrender much ground on the best success of her ministerial career: reducing net migration.

Tags: Commons, David Cameron, Immigration, Theresa May, Vince Cable