Pride organisers said the weather “won’t be stopping us” as the city’s parade got under way amid wet and rainy conditions.

Revellers turned out to cheer on the much-celebrated Pride event along the seafront, despite yellow weather warnings from the Met Office.

Saturday’s parade was expected to draw 300,000 people to the city’s streets, among them community groups, small businesses and NHS services, as they march to the official Pride community fundraiser Fabuloso in the Park at Preston Park.

Brighton Pride’s managing director Paul Kemp said: “We’ve encouraged people to wear ponchos so it might be a little bit Glastonbury.

“That wouldn’t stop us from having a great celebration and a great Pride in our city.

“Make sure you wear a poncho and slay that poncho, stay dry, look after your friends, don’t over do it, make sure you’ve got somewhere to stay and look out for people.”

The annual celebration is the city’s largest single event, expected to boost the economy by more than £20 million over the weekend.

However Govia Thameslink Railway will not be running any trains between London and Brighton on Saturday, blaming an overtime ban by the drivers’ union Aslef.

Mr Kemp said organisers were disappointed a compromise could not be found.

He said: “It will affect turnout absolutely because people will be cut off from the rest of the country.

“I’m sorry for people who booked hotels and paid for accommodation and now can’t get in.”

But he said it “won’t derail us” and “the show goes on”.

This year’s event, with the theme Dare To Be Different, marks the 50th anniversary of the first Brighton Pride march, organised by the Sussex Gay Liberation Front in July 1973.

Mr Kemp said: “Those early pioneers 50 years ago who put their head above the parapet in different times, it was a very different environment for LGBT people at that time.

“We’re recognising the trailblazers around the city, we have lamp posts around the city of people who have been part of the movement and are current trailblazers. We’re celebrating being different.”

He said that while Pride is about celebration it is also about protest and in the UK “we’re standing by our trans siblings”.

He added: “There’s a feeling from the LGBT community we’re being slightly politicised for political reasons, when people really should be focused on the real issues like the environment, cost of living, the things that really affect lives.”