The stars of the hit period drama will gather at London's Savoy hotel on Thursday (30Apr15) to bring in funds for the homeless charity Centrepoint.

The event will feature performances from the actors, and fans will be able to purchase tickets for $800 (£500) each.

Leech tells Britain's Daily Mirror newspaper, "The whole idea is you know the characters for who they are but they are going to get up and do something completely different."

Leech and Dockery will also be joined by fellow Downton Abbey star Laura Carmichael in September (15), when they take part in the inaugural Spotlight 10k Challenge run in London's Regent's Park to raise money for charity.