Duncan Welsh, head of events at The View from The Shard, has organised an improbable 154 private wedding proposals on the viewing platforms of Britain's tallest building – and he claims a 100 per cent success rate.

Maybe it's something about the air 802ft above London Bridge, but Welsh, whose job it is to pull off all manner of weird and wonderful events at the top of the skyscraper, one of the capital's biggest tourist attractions, says he hasn't seen a single refusal.

“I am not making this up but as yet we've not had a single no,” he insists. “I'm completely serious — and I often get people asking this. We've had 154 out of 154. It's amazing.”

The View from The Shard has always been a hotspot for proposals during its public sessions, but introduced a private proposals package this year when the events team realised the demand for it.

Events manager Duncan Welsh has organised 154 wedding proposals at the top of The Shard

That’s not to say that proposals in public sessions haven’t been equally impressive. One man recruited Welsh’s team to organise a choir to start singing his girlfriend’s favourite song. The flashmob pretended to be part of the paying crowd, then slowly emerged from among the ordinary punters, singing as he popped the question.

Quite romantic, despite the fact the song was Ed Sheeran's Thinking Out Loud.

At the time of writing there are no private proposals booked for Valentine’s Day 2017, but the team expects there to be several during public sessions on the day.

“As you're getting near Valentine's Day you can't go up there without hearing someone proposing,” Welsh says. “You're almost guaranteed.”

However, some clients’ ideas for private proposals turn out to be too romantic for their own good.

“Somebody, who really didn't understand why they couldn't have this, wanted the words, ‘Would you marry me?’ spelled out in lights on buildings across the London skyline.

“It's the kind of thing I would have loved to do, but it was just slightly beyond our remit, persuading half of central London to turn its lights off at a given moment.”

This year, The View from The Shard has launched a wedding package, so along with London’s highest proposals, it will also be home to the highest hitches. (We're discounting aircraft, by the way. That's cheating.)

But romance aside, events management at a venue like this is hard work. The biggest success of last year, says Welsh, was probably the two-and-a-half-tonne igloo installed on level 72. It took seven hours and more than 20 journeys in each of The Shard’s four lifts to transport it.

But some events even Welsh has had to turn down for practical reasons — for example, a roller disco.