The wrangle between a Kingston environmentalist and the Metropolitan Police over the legality of monthly bike rides in the capital could be taken to the House of Lords.

Cyclist Des Kay plans to take the Critical Mass Cycle Ride dispute further after the Court of Appeal's decision today.

Two out of three judges overturned a High Court ruling that the rides do not need to have prior permission from the police.

Des, environmental campaigner of the year at the Green Guardian Awards in 2006, challenged the Met in June 2006 over claims the events were unlawful and that people taking part could face prosecution.

The High Court ruled that advance notice of the rides under the Public Order Act 1985 was not necessary after lawyers argued it fell within an exception for processions that are "commonly or customarily held" but the Met appealed the decision.

Phil Michaels, Head of Legal at Friends of the Earth Rights and Justice Centre and solicitor for Des Kay, said: "We are in an unusual situation where the police's appeal has been successful even though, over two separate hearings, three judges have found in our favour and only two have found against us.

"Although the result is disappointing, we are encouraged by the strongly worded dissenting judgments in our favour and hope that we are able to take this important case to the House of Lords."

On the last Friday of every month since April 1994, cyclists have gathered on the South Bank for an evening ride through London.

The rides are part of a global phenomenon in which cyclists in more than 300 cities worldwide take to the streets in a celebration of safe cycling.

Police handed out notices at a ride in 2005 and told people they would be breaking the law by taking part in an unauthorised procession.

"We cannot fulfil the Met's criteria for an organised route," said Des. "It's a planned spontaneous event with a bunch of people getting together with no particular destination in mind.

"I think more people than ever will be at the next ride on Friday to make a point."