Prince William admits a host of celebrities rejected the chance to support his mental health campaign because of the stigma surrounding the issue

He shared: "When we set up the campaign not one celebrity wanted to join us, not one person wanted to help with the campaign because it was mental health."

The Prince also claimed that British attitudes towards mental health can be traced back as far as World War Two, saying that a stiff-upper-lip approach has prevented some people from speaking honestly about their worries.

He explained: "I take it as far back as the war.

"It was very very difficult for everybody, losing so many loved ones and dealing with such horrendous circumstances that no matter how much you can talk you were never going to fix the issue.

"Completely by accident they passed that on to the next generation, we all learn from our parents we all learn from how they deal with things.

"So this whole generation inherited that this is how we deal with problems we don't talk about them. I think that now there's a generation here that's realising this is not normal and we should talk about them. We should get over it."

Meanwhile, Prince William also confessed that working in the air ambulance led him to retreat into his "shell".

He said: "I was dealing with a lot of trauma on a day in, day out basis, stuff that your body is not programmed to deal with.

"I might have gone into my shell a bit and thought 'I can deal with this myself' and then potentially down the line it manifests itself in a much worse situation."