A statue of a naked, pregnant woman with no arms has been unveiled on Trafalgar Square's fourth plinth.
The 12ft (3.6m) marble sculpture, "Alison Lapper Pregnant", is already dividing opinion among art critics and disability campaigners.
Artist Marc Quinn said he had sculpted his friend Ms Lapper because disabled people were under-represented in art.
The Disability Rights Commission called it "powerful and arresting", but one critic dismissed it as "rather ugly".
Ms Lapper, from Shoreham, West Sussex, sat for the artist when she was eight months pregnant.
She has called it a "modern tribute to femininity, disability and motherhood".
But she added: "It still daunts me now. I'm going to be up in Trafalgar Square. Little me."
Mr Quinn spent 10 months working on the statue in Italy from a single piece of white marble.
"I felt the square needed some femininity, linking with Boudicca near the Houses of Parliament," Mr Quinn told BBC News.
"Alison's statue could represent a new model of female heroism."
But Robert Simon, editor of the British Art Journal, said: "I think it is horrible.
"Not because of the subject matter I hasten to add. [I have a] lot of time for Alison Lapper. I think she is very brave, very wonderful but it is just a rather repellent artefact - very shiny, slimy surface, machine-made, much too big... "
Bob Niven, chief executive of the Disability Rights Commission, said the statue at the heart of London would raise public debate on disability.
Other plinths in London's most famous square are occupied by equestrian statues of British Empire heroes.
The fourth was intended for a King William IV statue, but a lack of funds meant it remained empty.
Experts gave up trying to find a permanent fixture for it in the early 1990s, because no-one could agree on what was appropriate.
Some sculptures, such as Rachel Whiteread's Monument - a transparent resin cast of the inside of the granite plinth itself, were put up temporarily.
But in 2003, mayor Ken Livingstone had backed a review group's suggestions that it should be used as an ever-changing display of artworks.
The mayor, who has had the square partly pedestrianised and wants it to become a cultural focus for London, commissioned six artists to come up with ideas for the plinth.
Alison Lapper Pregnant is one of two works selected from the shortlist.
It will be displayed until April 2007 when it will be replaced by Thomas Schutte's Hotel for the Birds.
What do you think of the latest addition to Trafalgar Square's fourth plinth?