Donald Macintyre's Sketch: Dave carried gamely on – alarm bells ringing

Making his big immigration speech – pivotal, most important of the year etc – David Cameron faced handicaps, unforeseeable at the planning stage. You wouldn’t choose to make it the day after the immigration figures had propelled not so much a coach and horses as a convoy of Abrams tanks through your promise –“no ifs and buts” –to bring them down. Neither would you choose to lose two MPs over the issue and least of all to compete with an ear-jangling alarm. And lose.

He did as well as anyone could in these adverse circumstances, as much for what he didn’t say as what he did. No EU immigrant quotas. No toxic “swamping” rhetoric. No overblown threats about leaving the EU (beyond the formula, to which he stuck doggedly under questioning, that he would “rule nothing out” if he didn’t get his way in EU negotiations, which he hoped, however optimistically, he would). No “emergency brake”.

There was however an er ... emergency break. It seemed thin recompense for having live coverage product placement to die for, that it took so long for anyone at JCB, at whose West Midlands plant the PM was speaking, to turn off the alarm which interrupted him. “This has clearly set off alarm bells in the European Commission ...,” he ad-libbed gamely. (He had just promised to reduce “exceptionally” high immigration from the EU when the wretched thing went off). He sipped some water. Then tried to resume above the din: “I am completely committed to delivering ....” And sensibly gave up.

He then chuntered on amiably about how he had once had to speak louder and louder at a car plant and how he was sorry to have stopped production at JCB but they could get back to it as soon as he finished – hint, hint. And it finally stopped.

Surprisingly, some of the subtext was a cri de coeur to his European partners: As in: “all these benefit cuts are the least I can get away with here. You know they make sense for you too. So please help me to stay in by agreeing to them.”

But it also owed something stylistically to Tony Blair, especially the classic setting up of opposites only to denounce them. Like those who think immigration “isn’t a problem at all” and those who “demonise” immigration, offering the “snake oil of simple solutions”– get it, Ukip? At one point he even condemned the “false choice” (copyright T. Blair) “between the status quo or leaving [the EU]”. At this rate he’ll soon be babbling about a “third way”.

Meanwhile, the PM seemed to have very marginally under-shaved above his upper lip. On Wednesday, congratulating two MPs on their Movember growths, Cameron said mysteriously: “I can’t seem to be able to join you.” Is he nevertheless trying a new pre-election look? Unkind critics suggest his Madame Tussauds waxwork, also now sporting a Movember moustache, makes him look like a cross between Lord Lucan and Basil Fawlty. But with the polls this close, anything is worth trying.