Kate Middleton hosted a special reception at Kensington Palace on Wednesday (19 April) for a group of runners who are representing mental health campaign Heads Together at the London Marathon.

The campaign to generate awareness of mental health issues, which has been championed by the Duke and Duchess of Cambridge and Prince Harry, has been chosen as the official charity for this year's 26.2-mile race.

The 35-year-old dressed down for the casual gathering, wearing a £220 white, blue and red-striped top by Italian designer Luisa Spagnoli, matched with skinny jeans and her favourite trainers.

The mother-of-two looked relaxed as she interacted with the athletes, who sported blue vests and the now familiar headbands bearing the charity's logo.

With the support of the Royal Mail, the headbands will adorn 70 London postboxes along the marathon route.

Royal Mail CEO Moya Green told Mail Online that the company recognises the importance of the campaign. "As a large employer, we recognise that we have a big role to play in tackling the stigma surrounding mental health. I am proud that we are using our iconic post boxes to support Heads Together and this important campaign."

Heads up for landmarks

Landmarks in the capital will also be "wearing" the headbands on Sunday including Battersea Power Station and the Olympic Stadium, while several waxworks at Madame Tussauds will do the same, including the wax likenesses of Prince William, Prince Harry, Usain Bolt, Mo Farah, and Will.i.am.

Speaking with Jamie Maloy, headteacher of Viking Primary School, Kate reportedly praised brother-in-law Prince Harry, who in an unprecedented interview with The Telegraph opened up about his own struggles to express his emotions following the death of his mother, Princess Diana.

"What I love is your brother-in-law talking the other day, because that's just ignited it," said Mr Maloy.

He described Harry "as a real hero to a lot of people" for his candour and for opening up the discussion about mental health, prompting the Duchess to reply: "Absolutely. He's been brilliant!"

She also wished the runners luck as they prepare for the marathon. Kate and Prince Harry will be personally cheering them on from the sidelines.

The young royals launched the Heads Together charity last year in a bid to remove the stigma surrounding mental health issues and have been campaigning ardently on behalf of the charity.