Oxford's traditional May Day celebrations will be held on Magdalen Bridge for the third year running - and the turnout could be bigger than ever.

The bridge will be open to revellers, although, like last year, there will be a drinking ban as it falls within the city's alcohol-free zone.

This year's event is expected to attract record crowds because it falls on a Saturday.

Last year - a Thursday - there was a limit of 8,500 on the bridge, but the last time May Morning was on Saturday, in 1999, there were 11,000 revellers.

Thames Valley Police and Oxford City Council, which jointly supervise the celebrations, have warned revellers not to try the 'traditional' leap into the river due to the danger of fast-flowing water and underwater objects.

In 1994, 22 people were injured, some seriously, after jumping into just 4ft of water.

Stewards and barriers will be in place to deter jumpers, while alcohol 'amnesty bins' will be provided on both sides of the bridge.

Chief Insp Chris Parker-Towle said officers would be on duty for public safety reasons and not to enforce the alcohol-free zone.

"We're quite sympathetic to the Students' desire to celebrate May Day and will not be throwing a wet blanket over the celebrations," he said.

"The priority for us is making sure no-one gets hurt and that everybody is allowed to enjoy the celebrations peacefully."

Helena Puig Larrauri, president of Oxford University Students' Union, said students, who will be allowed to drink alcohol in High Street as it is not covered by the ban, would understand.

She said: "Lots of people in a confined space carrying glass bottles doesn't make for a good party."

Crowds were not allowed on to the bridge between 1998 and 2001 because of concerns about the parapets, which have been strengthened.