It's not often you see a future king break down in tears.

But Prince William couldn't hide his anguish as he discussed the devastating impact of suicide with a mother whose husband took his own life just five days after their one-year-old son died.

In a deeply moving conversation to mark World Mental Health Day, the Prince of Wales's voice broke and he squeezes his eyes shut as Rhian Mannings told him how she desperately wished her late husband, Paul, had spoken to her about how he was feeling.

'I think that's what the hardest thing is… we would have been OK,' she said.

The film was shot earlier this month at Mrs Mannings's home in Cardiff.

Little George was her and husband Paul's third child, a smiley, giggling baby who was crawling everywhere and had just learnt to say 'hiya' when he celebrated his first birthday in February 2012.

A week later he suffered a seizure but tragically died just two hours after being rushed to hospital. He was later found to be suffering from pneumonia and influenza A, which can be symptomless.

While Rhian and Paul initially comforted each other, he soon began to blame himself terribly, saying he had let his family down.

Five days later he went out for a drive - and never returned.

The years since have been painful, although Mrs Mannings has been awarded an MBE for her work setting up the charity 2 Wish Upon A Star, which has helped more than 3,000 people in Wales affected by the sudden death of a child or young person.

But it is clear that the pain still remains.

The new film saw the future King visit Mrs Mannings, 48, for a cup of tea and Welsh cakes - made by her mother - to talk about her experiences. The pair have met previously.

'Would you like to put them on the plate?' she asked him, offering the cakes.

'So, how have you been though, Rhian? Because obviously I haven't caught up with you for a long time,' William said.

'You know, it's up and down, everything's up and down, life's up and down anyway, isn't it?' she replied.

'Absolutely,' answered William, who with the cancer diagnoses of both his wife and father has been through a difficult time of his own.

After exchanging news about family, William asked: 'Rhian, how have managed to bring up your children so brilliantly, as you have? How have they managed to thrive? '

'They've just grown up to be incredible kids and young adults, I look back and I don't I still don't really know how we survived it. People ask me that a lot, like "How do you do it?", and I don't really know,' she shared.

'They were so young, the memories they've got now are memories that probably I've placed into their minds. I still worry a lot about what tomorrow is going to bring our family. But I'm trying to be rational and trying to think positively. I just want my children to be happy.'

William spoke about the 'stigma' that still exists around the issue of suicide, and the difficulty for families of whether to talk about it.

'I think it's important never to lie... There's ways in being truthful and just being gentle. As a parent, you know your children better than anybody else,' she remarked.

William added: 'From the families I've spoken to who have had to endure suicide. There's a lot of unanswered questions that live with you forever, really, don't they?'

'I will forever go over those last few days with him, wondering what I missed. Before we lost George, we were just so happy. And I think this just shows that it really can happen to anyone,' she said, sadly.

 'If you could say something, or wanted to say something to Paul. What would you… what would you have said?' he questioned.

'There's only one thing I would ever say to him if I had time with him. And that would be, "Why didn't you speak to me?",' she admitted.

'I think… I ask myself that every single day. He was absolutely devastated, he did keep blaming himself that weekend. But I would just like to sit him down like this and just say "Why didn't you come to me?" Because he's missed out on just so much joy, and we would have been OK. And I think that's what the hardest thing is, we would have been OK.'

At this point she could see that the Prince is struggling.

'Are you OK?' she asked gently.

Shaking his head and holding her hand, the Prince replied: 'I'm sorry. It's just it's hard to ask these questions that I… '

'No, it's fine. It's just you've got children,' Mrs Mannings told him gently.

'I know, I know… It is…' the royal trailed off.

'It's hard… And you've experienced loss yourself,' she reassured him.

'It's ok,' William replied.

'Life can throw you these awful curve balls, but by talking about it by, you know, having hope you can continue,' she added.

William, who by now has managed to pull himself together, agreed, saying: 'The best way to prevent suicide is to talk about it. Talk about it early, talk about it with your loved ones, those you trust, your friends. So thank you for talking about it.'

 Mrs Mannings's mother also came in at one point and William thanked her for some Welsh cakes - and promised he would take them home with him to eat in the car.

The family, including Mrs Mannings's other children, Holly, 17, and Isaac, 16, laughed together as they realised that the future king has gone off with their granny's Tupperware box.

'He's taken your Tupperware! ' she giggled. 'Not really a typical Thursday...!'

The touching film of their conversation has been released to mark the launch of The Royal Foundation of the Prince and Princess of Wales's National Suicide Prevention Network, backed by more than 20 organisations and funding of more than £1million from the couple.

Over the next three years they hope to tackle the root causes of suicide and create a single, universal pathway for suicide prevention which is evidence-based, effective and accessible to all.

The Network will be chaired by Professor Ann John, a leading expert in the prevention of suicide and self-harm, and will cover all four home nations of the UK.

Preventing suicide is a complex challenge, shaped by social, economic and personal factors, meaning no one-size solution fits all.

Latest figures show 7,055 deaths are caused by suicide in the UK every year.

In a statement The Prince of Wales said: 'The incredible partners who form this network reach those at risk of, or affected by, suicide with their inspirational work.

'I have had the privilege of meeting all of the founding partners to see firsthand their powerful community-based efforts to offer hope and support to those who need it most.

'Their efforts reaffirm the urgent mission of the National Suicide Prevention Network: to build a bold, unified national response to the heartbreaking—and preventable—tragedy of suicide.'

Speaking of her family life and personal experiences, Mrs Mannings added: 'We just presumed life would take us on that normal journey of growing old together. I'd only been back teaching a couple of days after my maternity leave.

'When George fell ill at home very suddenly. So we had to call an ambulance to come out to the home, he was rushed to hospital.

'You never think anything bad is going to happen, because this is your family. You see these things happen on TV. But sadly, George was very poorly, and within two hours of being admitted to the hospital, he died.

'Five days later, after we lost George, probably the unimaginable, really, happened. Something that we could never have ever been prepared for, totally unexpected... Paul walked out of the house and took his own life.

'It's really difficult to explain how grief feels. Emptiness, physical pain, your heart hurts You know, your limbs hurt, you ache, but when you lose somebody to suicide, it leaves so many questions unanswered.

'But I'm hoping by having increased awareness around what it is, but also the effects it has on those left behind. What causes people to walk out and never come home.

'Let's stand together, let's talk about it. Let's get people in the public eye talking about it. We can help each other, this really doesn't have to be what happens.'

If you have been affected by any of the issues raised in this story, information and support can be found at the Hub of Hope, the UK's largest mental health support directory: https://hubofhope.co.uk/.

For confidential support, call the Samaritans on 116123 or visit a local Samaritans branch. See www.samaritans.org for details