The double doors opened and in walked the most important man in Britain. Quickly followed by David Cameron. £14bn might be loose change to China, but it's a massive trade deal for Britain, and the prime minister had gone out of his way to give Chinese premier Li Keqiang the red carpet treatment. First he'd hastily fixed up a last minute cup of tea with the Queen – "Do you want the Civil List or not, ma'am?" – then he'd fast-tracked visas for Chinese millionaires. As the coup de grâce he had wheeled out several members of the cabinet for the signing ceremony in the Laurence Llewelyn-Bowen designed Grand Locarno ballroom in the Foreign Office.

Li was clearly having a great time. He was relaxed and jokey, everything a Chinese leader is not meant to be. It was Cameron who was feeling the strain: spending a couple of days as tour guide and valet doesn't come naturally to him. He tried to summon one last smile. "When Premier Li was first here four years ago, he gave my daughter Florence a toy panda," he said. "Now she has grown and the relationship between our countries has grown." You won't hear a more blatant appeal than that. Gimme some pandas. Now. Three if poss, so that we've got one more than the Scots if they vote for independence.

No pandas were forthcoming, so Cameron tried another tack. "It is 30 years since we signed a declaration to hand over Hong Kong," he said. It is also 25 years since Tiananmen Square but he stopped short of announcing an issue of new stamps to commemorate that.

Li responded graciously, as one might expect of a colonial governor bestowing largesse on his new dependency. He had much enjoyed meeting the Queen, he said, and was looking forward to "creating huge energy". Presumably a reference to the deal that the French-owned Hinkley Point nuclear power station was to be financed with Chinese money.

Cameron was still just about holding his own until BBC correspondent Carrie Gracie asked Li a question about Chinese human rights abuses in Mandarin. At this point, the simultaneous headphone translation failed. Li was unbothered as he delivered a lengthy reply, but Cameron started to look around anxiously, before narrowing his eyes in a manner that suggested if he concentrated very hard he might just become spontaneously fluent in Chinese.

Thereafter, there were long delays as the translators took centre stage. Despite speaking at breakneck speed, the Chinese translations of Cameron's remarks took far longer than the original English. "I'm sorry everyone," the translator might have been saying, "but this bloke keeps going on about the EU and other stuff we don't care about. Don't worry, though, hopefully the sales and marketing team from Burberry will be here soon."

From then on the Chinese premier was on a roll. Which is more important to China? he was asked. France, Germany or the UK? To be honest, was the gist of his reply, you're all basically no more than local provinces to us. So why had China said Germany was more important last week, and the UK this? "When you're in a local place, you sing local songs," he said. Or, in the immortal words of Midge Ure, "you mean nothing to me".

As the conference wound up Cameron scowled while Li smiled and waved to the press. Welcome to the new world order.