Jeremy Paxman, Twiggy, David Gandy and Louis Smith are asking the British public to turn their lights off to commemorate the centenary of the First World War.
The Royal British Legion has brought together veterans and famous faces to take part in the national initiative where communities across the UK are invited to switch off their lights and illuminate their homes with a single candle or light between 10pm and 11pm on August 4 - the date Britain entered the war 100 years ago.
The Legion said the Lights Out initiative takes inspiration from the "stirring" words of wartime Foreign Secretary Sir Edward Grey, who said on August 3 1914: "The lamps are going out all over Europe; we shall not see them lit again in our life-time."
Jeremy, who bowed out of Newsnight after 25 years last month, said: "Three quarters of a million men didn't return from the First World War. The so-called 'War To End War' didn't do so, more's the pity. That wasn't their fault. The least we can do is to remember them."
Charles Byrne, director of fundraising at the Royal British Legion, added: "Our vision is that over one million candles will be lit across the UK, commemorating every service man and woman who died during WW1.
"We hope to see candles lit at every war memorial, community centre and home in every village and in every community.
"This is one of a number of initiatives the Legion has undertaken to commemorate the anniversary of the First World War, when we hope to pass the torch of remembrance onto a younger generation ensuring there will always be a living legacy to those who sacrificed their today for our tomorrows."
The celebrities will feature alongside Chelsea Pensioners and service personnel in a video to promote the initiative.