Time to Change, which is run by charities Mind and Rethink Mental Illness aims to end stigma and discrimination about mental health problems and since launching in 2007 has gained the support of nearly 90,000 people.

Director of Time to Change, Sue Baker, said: "[This] reception, with the support of the Deputy Prime Minster, marks a major milestone for Time to Change.

"Over the last four years we’ve started to witness changes in public attitudes and more importantly behaviour. However, we must make sure that people of all ages and in all communities feel able to openly discuss mental health issues with ease and the expectation of support and understanding.

"It will take more than a few years to overturn decades of prejudice - this is the work of a generation."

New statistics released to coincide with the launch of the next phase of the Time to Change campaign reinforce its continued importance with only 15% of the British public saying they are truthful all of the time about how they’re really feeling.

Liberal Democrat leader Clegg added: "Challenging attitudes and behaviour is essential if we are to ensure that people with mental health problems feel able to talk openly about their illness, just like other physical illnesses."

The other celebrities at the event all spoke about the help they received to overcome difficulties posed by mental health problems to enjoy success in their respective careers and Rugby World Cup winner Jonny Wilkinson has also written a blog about his his battle with depression which you can read here.

Time to Change supporters (l-r) Alastair Campbell, Fiona Phillips, Nick Clegg, Care Minister Paul Burstow, Trisha Goddard & Marcus Trescothick