What Boris Johnson and Prince Charles discussed over tea and croissants remains a mystery

It was the tete-a-tete that had been the talking point of the week.

Would either the Prince of Wales or Boris Johnson dare to raise the thorny issue of the Rwanda migrant policy?

Would the Prime Minister wade in with a robust defence of the government strategy that the Prince is alleged to have described as “appalling”?

The meeting, at Kigali Convention Centre, was the first between the two men since the heir to the throne’s alleged comment, made in private, became public.

It was originally billed by the Prime Minister’s official spokesman as a “bilateral discussion”.

But Clarence House swiftly played down the event, instead insisting that Mr Johnson would be “popping in” on the Prince for a cup of tea and an informal chat.

Mr Johnson had vowed to defend the policy, suggesting he would explain to the Prince the error of his ways and tell him to keep an open mind.

Again, that approach was quashed by the Prince’s aides, who appeared mildly frustrated as they insisted the subject was highly unlikely to be raised at all.

Calls are thought to have been made behind the scenes and Number 10 soon changed tack, suggesting that the conversation would centre on "key issues of importance to the Commonwealth", such as sustainability, girls and education.

In the event, the highly anticipated meeting lasted just 15 minutes and 10 seconds.

The two men, both in blue suits, posed rather awkwardly for the cameras before getting down to business behind closed doors.

Mr Johnson was first to arrive at the rather drab conference room, followed a few minutes later by the Prince.

They stood before the Commonwealth flag making small talk as the photographers clicked away.

The Prime Minister tried to lighten the mood, jokingly asking the small gaggle of press: “Who are you?” The Prince stood a little more stiffly, one hand in his pocket, but they briefly made small talk and he managed a chuckle before the two men took their seats.

After the television camera, press photographer and two No 10 staff - one videographer and one photographer - were shown out, the aforementioned tea was wheeled in.

Croissants and snacks were laid out on a table but whether either man had any appetite for pastries, never mind the discussion, was not confirmed.

'Good old chinwag'

Mr Johnson was the first to leave, brusquely striding away to attend another meeting.

The Prince’s private secretaries were then invited into the meeting room for a debrief with their principal, before the royal party left around eight minutes later.

What was - or was not - discussed so far remains unknown.

Mr Johnson later declined to divulge the topics discussed, instead focusing on the positive comments the Prince had made earlier, in a speech to heads of government.

Asked about the one-to-one meeting, he said: "It was a good old chinwag and we certainly covered a lot of ground and there’s no doubt that when you look at, what you can certainly take away from what the Prince said today in his opening address to the summit, is that everyone can see the huge, huge progress that Rwanda has made.”