MUCH of what the prime minister had to say about immigration yesterday has been said before.

David Cameron pledged to reach an annual net migration figure - the genuine number by which migrants increase the UK population - of no more than 100,000.

If that sounds familiar it is because it is the same target Mr Cameron announced when he became prime minister in 2010.

His renewed determination yesterday to hit the target came on the day it was announced that net migration last year was 318,000 - an annual increase of more than 50 per cent and the highest figure for more than a decade.

Mr Cameron announced a raft of new measures yesterday aimed at controlling immigration. These included enabling the courts to seize the wages of illegal workers as proceeds of crime.

Tough as Mr Cameron’s words were, the biggest problem facing his government on this issue is that no-one knows how many illegal workers are in the UK.

Treating them as criminals is one thing; actually finding these people is quite another.

While what Mr Cameron had to say yesterday was largely old news, there was one new line in his speech that we suspect will become something of a government mantra.

It goes something like this - if anything went wrong during the period of coalition government, blame the Liberal Democrats for it.