Artist David Shrigley with the sculpture.

London - A giant hand with a thumbs up has been unveiled as the new artwork occupying the fourth plinth at London's Trafalgar Square.

Mayor Sadiq Khan presented artist David Shrigley's sculpture Really Good , a seven-metre high hand with a long thumb cast in bronze, saying it represented “optimism, positivity, the best of us”.

The plinth, built in 1841, was meant for a statue of King William IV but stood empty because of lack of funding.

More recently, it has hosted various commissioned artworks.