Controversy was today raging over the art works that have finally been chosen to occupy the empty fourth plinth in Trafalgar Square.

A white marble sculpture by Marc Quinn of disabled artist Alison Lapper, when she was eight months pregnant, and another modernist concept called Hotel For The Birds, by German artist Thomas Sch¸tte - drew equal measures of contempt and praise when Mayor Ken Livingstone's Four Plinth Commissioning Committee announced the winners today.

Quinn's Alison Lapper Pregnant will rest on the plinth for 18 months from next spring, to be replaced after that by Sch¸tte's Perspex work. He intended the image to counterbalance the heavy presence of military images in statues across London.

But there was vociferous condemnation of the verdicts by the committee of art lovers, chaired by National Portrait director Sandy Nairne and including Channel 4 news anchorman Jon Snow, Lazards merchant banker Diane Henry and disability adviser Richard Reiser.

The Evening Standard's art critic Brian Sewell damned the decision, saying: "I dislike the Quinn intensely and I can see no virtue in the Sch¸tte. It's a gloriously fudged decision and they better try and get it right next time."

David Lee, editor of art magazine The Jackdaw, described the works as "ghastly," while Robin Simon, editor of British Art Journal, said: "Thankfully, these sculptures are not going to be around for ever."

But Jay Jopling of the White Cub Gallery which exhibits Quinn, said: "I don't see how anyone could find this work sensationalist. It's a major work of art, drawing on tradition and context, very rich and layered."

And Bert Massie - chairman of the Disability Rights Commission - said: " Congratulations to Marc for realising that disabled bodies have a power and beauty rarely recognised in an age where youth and 'perfection' are idolised."

The committee - publicly funded to the tune of £80,000 a year - chose the winners from a shortlist of six, which included a Ford Fiesta covered in pigeon droppings and two wooden lifesize effigies of Tomahawk Cruise missiles.

Londoners had already given their own artistic judgement through an Evening Standard poll which suggested that around 70 per cent rejected all of the proposed works.

Tens of thousands more also messaged a plinth website with their suggestions about what statue or work should occupy the plinth.

The Greater London Authority admitted today that many of those voting on its website were against the idea of contemporary art in Trafalgar Square. Most would have preferred an iconic or historical figure to occupy the plinth, originally erected in 1841.

However, quite what it is Londoners said is today unclear - because the Mayor's committee refused to reveal which of the original six shortlisted works emerged as the favourite of the tens of thousands of people who expressed their opinion, either on the lavish Fourth Plinth website or at a National Gallery exhibition dedicated to displaying the choices.

Asked what the public's favourite was, Mr Nairne said: "All I'll say is that there were a lot of comments in different directions, positive and negative. What we were really interested in was getting a gauge."

He added: "At the end of the day it was an artistic judgement."