SHOCKED onlookers choked on their ice-creams as dozens of cyclists rode through York city centre - naked as the day they born.

Members of the 50-strong group, who were given a police escort by fully-clothed cycling officers, got their kit off yesterday evening to raise awareness about environmental matters such as our dependence on cars and oil.

Some of the cyclists chose to stay fully-clothed, wear pants and G-strings, or paint themselves silver, while others went for the naturist look.

One man joined the ride on a unicycle dressed as Santa Claus to highlight the dangers of global warming. He held aloft a banner which read: "Father Christmas says no to climate change".

Kay Watkins, of Holgate, York, got her friend to paint her naked body for the ride, but said she was nervous at the prospect. "It's really exciting, " she said. "I've spent a lot of years campaigning."

A 40-year-old naturist called Steve, said: "Why should we cover up our bodies on a sunny day like today? It gets across the message that we need more cycle tracks."

The ride started at Lendal Bridge, passed the Minster and continued up to the Millennium Bridge, before finishing at the Museum Gardens.

One group of men stripped off and joined the ride on their bikes for no other reason than to have a laugh.

Among them was Christian Potter, of Acomb, who said: ""I'm not really interested in the issues, but it's a sunny day and I've had a beer."

But not everyone appreciated the extraordinary spectacle. Father-of-four Steve Noble, 26, of Acomb, York, was shocked to be faced by the group riding passed as he walked out of the Museum Gardens with his family.

He covered his children's eyes and shouted at the group to put some clothes on.

"It's absolutely disgusting, " he said. "They should all be arrested. I can't believe the police would let it go on."

Sergeant Dave Horn, who co-ordinated the police cycling operation, said officers rode with the group at the front and rear to maximise safety. Traffic was prevented from overtaking the cyclists.