Nick Clegg succeeded in uniting Conservatives and Liberal Democrats together as he never has before. What an unexpected shot in the arm this lunchtime's PMQs was for the coalition.

It was not supposed to be like this. Behind closed doors Clegg and David Cameron are engaged in a bitter standoff over boundary changes. Tory and Lib Dem party strategists are frantically trying to come up with ways of doing well at the next general election, even if that means ruining the coalition. This week we are exactly midway through this government's life, and the expectation was that the cracks would be starting to show.

Then, seconds before the Speaker called on the absent prime minister to begin the session, George Osborne very kindly poured a glass of water for Clegg. He had been talking amiably with Vince Cable, viewed as an enemy of business in No 11, so coalition fraternising levels were unusually high. All the signs were there for those to spot them.

With David Cameron off in the Middle East, shaking his fist across the Syrian border, Clegg set to his task with aplomb. He got a huge cheer from all sides when congratulating Barack Obama on the president's re-election. "I expect that's the only point I will be cheered today by the opposition benches," he joked. Clegg is used to be being bashed, and has developed a thick skin as a result.

With deputy leader Harriet Harman taking on offensive duties in Ed Miliband's stead, he didn't need it. After a couple of boringly bipartisan questions about Leveson, she finally got her attack started with a set of questions about childcare. They were a little wonkish and completely ineffective. Clegg dealt with them calmly, apart from one moment when he mounted an undignified retreat to the economy as a get-out-of-jail attack. Labour MPs screeched with laughter at how unsubtle he was being. Yet the Tories found themselves cheering in support of Clegg in response. The deputy prime minister was getting away with it, and in style.

Maybe that was the moment when he decided to go for it. From then on, Clegg had the Tories behind him, and neither side were going to let go. The deputy prime minister's final coruscating indictment of Labour's record may have been full of desperately old clichés about 'cleaning up Labour's mess', but it didn't matter. The entirety of the government benches yelled their support. Osborne repeatedly nodded his head thoughtfully, looking out of the corner of his eyes, as Clegg soaked up this unusual approval. The chancellor was obviously impressed.

So it continued. There was not a single hostile question as the session went on. The biggest threat to Clegg's composure appeared to be his voice, which was becoming increasingly gravelly. By the end it looked like it was going to disappear completely.

The session finished with a question from Peter Bone, perhaps Clegg's most openly outspoken enemy on the Conservative benches. Not today. Bone had decided to be good, singing the praises of the coalition "when two parties get together in the national interest". Clegg was flabbergasted. In his best Marge Simpson impression he declared his wish to "savour and treasure this moment". He's never experienced anything like this before.