Samantha Cameron and her two older children, Nancy, 11, and Elwen, 9, were in the gallery just beside me for PMQs – and they chose a belter. 'There's going to be quite a lot of shouting,' I heard Mrs Cameron warn the youngsters as the House assembled below us. There sure was. This was the last PMQs of the Parliament. For either Dave or Ed, this was possibly the last hurrah at the despatch box. As the Prime Minister took his seat he looked up and spotted his children. An enormous beam lit his face and he winked at them. But as he read his usual opening spiel about having 'further such meetings today' he shot the Speaker a rueful little smile, plainly acknowledging that the precious formula of words – used by premiers for decades – might never again fall from his lips. Scroll down for video . Mr Miliband was left flustered after Mr Cameron was happy to rule out a VAT increase during the PMQs . After that momentary wobble, Mr Cameron proceeded to do to Ed Miliband what your average food processor will do to a bunch of browning bananas. Magimix time! Mr Miliband had seemed sure he had the zinger par excellence with which to undo his great rival. The Labour leader stood at the Table, feet planted wide, a superior twitch on his lips as he leaned into the microphone. After a drollery about Mr Cameron's 'retirement plans' (that TV interview which has so excited the PM's more crosspatch critics), Ed Mil' challenged the PM to give a straight answer to a straight question. 'Will he now rule out a rise in VAT?' asked Mr Miliband. Mr Cameron: 'Yes.' Oops! That wasn't meant to happen. Mr Miliband had been expecting the PM to give a waffling non-answer. All his poise had been predicated on that. The eyebrow had been raised in a doubting manner as he put the query. His tone had been sarcastic. He knew – just knew – that Cameron would not be able to give a straight answer. Instead, the low swine had coughed up a horribly direct, undeniable, comprehensible 'yes'. What a filthy trick. Not fair, ref! The Miliband team had spent hours finessing follow-up attack lines. They had envisaged accusing the Tories of failing to be clear about their VAT plans. Now the so-and-so Cameron had gone and ruled out any such rise. Darn Tories. You can't rely on them to do ANYTHING. From my perch I could not see Mr Miliband's eyes but a colleague who was watching him reports that they revolved like a couple of fruit-machine dials whose lever had just been given a mighty yank. His cheeks were sucked in, as were the curtains in Dorothy's bedroom as the tornado strikes in The Wizard of Oz. The whole House was taken by similar surprise. There was an initial silence, as perhaps happens immediately after a bomb blast before car alarms start to ring. Had one of Labour's main themes for the general election just been obliterated? It did look horribly like that. Labour MPs sat stony-faced as Tory MPs roared with laughter when Mr Cameron ruled out a VAT increase . Er ,er, er, er: the Miliband mainframe went into catastrophic systems freeze. He sounded as though he had just swallowed a Rubik's Cube whole. 'Let me say to him, let me say to him, let me say to him,' he jibbered, gulping for air. Then, with desperation: 'Nobody's gonna believe him! Nobody's gonna believe him!' This drew laughter from the Government benches, aghast silence from Labour. Lucy Powell, Labour election supremo, was sitting beside Mr Miliband. She was doing one of those tombstone grins they do in the Tom & Jerry cartoons before all the teeth drop out. Mr Cameron capitalised on the ambush (which, one hears, may have been arranged with George Osborne). He pounced on Labour confusion and asked Mr Miliband if he would reciprocate by ruling out a Labour tax rise on national insurance. Naughty. After all, PMS is meant to be about questions TO the prime minister, not from him. Speaker Bercow let it pass and Mr Miliband flailed. He offered no such promise on national insurance, allowing Mr Cameron to clinch the moment by accusing Labour of a 'jobs tax bombshell'. Only later in the afternoon did a somewhat panicked Labour high command deny that it will hike national insurance tax. By then the moment had largely passed. Mr Cameron appeared to be enjoying his time at the Despatch Box, with wife Samantha and children Nancy and Elwen looking on from the public gallery . The Government benches were in loud, rampant tumult. Sir Bob Russell (Lib Dem, Colchester) hoiked up his trouser legs to betray two horrendously yellow socks (he had a yellow waistcoat, too). Keith Simpson (Con, Broadlands) waved a large, florid mouchoir. Beside me, young Nancy and Elwen grinned enormously and Nancy clenched her fist, punching the air with a 'Yes!'. She is like this aged 11? Crumbs. By 30 she'll probably be running a multinational. Or the country. Behind the Cameron family party sat another notable visitor: Geoffrey Boycott, cricket commentator and Yorkshireman. Boycs kept his counsel but if he had been offering commentary box analysis of the session one fears he might have talked of Miliband's stoomps bein' uprooted. This was a comprehensive clattering of a disorientated, dazed Miliband. It was a high-velocity whizzing which left the Labour leader a sorry, smoothiefied splodge on the floor. Game on.
Samantha Cameron and her two older children watched on during PMQs . They proceeded to see their father, the Prime Minister, trap Ed Miliband . The Labour leader was left flustered after Mr Cameron ruled out a VAT rise . His floundering reaction caused laughter among the Tory backbenches .