Singers Alesha Dixon and Pixie Lott are to perform at a concert launching the Royal British Legion Poppy Appeal.
The pair, who are the faces of the Poppy Appeal 2012, will star at the free event in Trafalgar Square in London marking the start of the Legion's £42 million fundraising drive.
The concert will also feature The Military Wives Choir and James Fox, star of the West End musical Let It Be, who will sing the official Poppy Appeal 2012 single Landlocked.
Alesha, a Britain's Got Talent judge and former Strictly Come Dancing winner, whose hits include The Boy Does Nothing, will perform with The Corps of Drums of the 1st Battalion Coldstream Guards and 1st Battalion Irish Guards.
Pixie, whose number one hit singles include It's All About Tonight, will appear alongside trumpeters from the Band of the Grenadier Guards.
The appeal's £42 million target is up on the record £40 million raised last year. People wishing to donate can do so at any time through the internet or by text.
Poppies will go on sale from Saturday until November 11, at locations across the country including train and Tube stations and shopping centres.
The act of observing a two-minute silence each year on November 11 began in 1919, following the Armistice agreement between the Allies and Germany at 11am on November 11, 1918, the end of the First World War.
The Royal British Legion spends £1.7 million a week on care and support for military families, including grants, employment advice and funding, emotional support, tribunal and inquest advice, care homes and family breaks.
Its work includes help for service personnel returning from Afghanistan as well as those from past conflicts.