DAVID Cameron did his best to convince voters that he could achieve his “no ifs, no buts" target of getting net migration down to below 100,000 a year but the only person who seemed half-convinced was the Prime Minister himself.

Under feisty exchanges from Sky’s interrogator Faisal Islam, Mr Cameron looked on this subject like a dodgy second-hand car salesman, trying to convince a wary customer that the rust bucket before him was in fact a gleaming classic model.

But the fact is the net migration figure at present is over 300,000 and heading in the wrong direction.

The PM sought to convince us that the figures had some years earlier been broadly in balance and it continued to be the “right ambition for Britain” to maintain the five-figure target. But when he was asked when such a miracle would arrive, he replied: “I’m not going to put a figure on it.”

Mr Cameron was on safer ground when he spoke forcefully about the single market and the economic “shock effect” Brexit would have. New tariffs on goods outside the EU would “hammer our jobs.” Leaving would be an act of “economic self-harm”.

While the Outers bang on about sovereignty and wresting back control from Brussels, the Tory leader insisted being in the single market but not having a say over its controls did not “mean you have more sovereignty”; it meant you had less.

After batting back what he called a phoney statistic about how many times the European court had overruled Britain, the PM resorted to the classic politician’s manoeuvre whereby he asked himself a question. “If you are saying, are there frustrations? Yes, of course.”

On scaremongering, Mr Cameron was again on the backfoot, insisting the words “World War Three” had never passed his lips and claimed that he was making a positive case for staying in the EU. Honest.

He was accused of a “classic Cameron fear campaign,” which he had deployed in the Scottish referendum. But, of course, he won that one.

The PM was confronted over Turkey’s desire to be a member of the EU and fears over terrorism. But he insisted there was no such prospect of Turkey joining for decades; it would be the year 3000 before it ever joined the euro club.

But his questioner did not seem convinced, declaring: “I’m an English Lit student and I know waffling when I see it.”

In the end, Mr Cameron succeeded by not failing and, addressing the audience, made an emotional pitch for people to stay in, urging parents to think about their children and their grandchildren.

“Let us not roll the dice on their future,” he declared. With so many people still undecided, it’s a pitch that might in the end just swing it.