Cyclists are being warned not to take a dangerous route home after an annual bike ride.

Sussex Police has put up a handwritten sign telling cyclists not to use the M23 to get back to the capital after the London to Brighton bike ride on June 21.

The sign has been fixed at junction 11 where the A23 becomes the M23 to remind the 27,000 cyclists expected to take part in the annual event that they are not allowed to ride on the motorway.

A Sussex Police spokeswoman said although it was normally the job of the Highways Agency to put official signs on the roads, officers had erected the temporary signs ahead of the ride.

Southern and First Capital Connect have banned bikes on their return train services in the Sussex coast area on the day of the ride, meaning that competitors will have to find other means of transport to return to the capital.

Police are concerned that some cyclists could decide their only option is to try to cycle home along the busy motorway.

Last year Marie Vesco was killed in an accident on the A23 as she and a group of friends made their way to a smash EDO protest in Brighton.

The London to Brighton bike ride stretches more than 54 miles and has been taking place since 1980 to raise money for the British Heart Foundation.