Extinction Rebellion protesters – accompanied by a boat – have blocked a street in Brighton as they demonstrate outside the Labour Party conference.

Environmental activists have turned out in their hundreds at the seaside city, causing traffic to back up along the coast earlier on Sunday.

It comes just a day after lorries at the Port of Dover were brought to a standstill for a brief time as protesters imposed a “blockade”.

Sussex Police is aware of the protest and drivers are being advised to avoid the area.

This morning the protesters unveiled “Greta”, a combination between a lighthouse and a boat, which has formed the centrepiece of the march.

The ship played an “alternative shipping forecast”, warning: “Crisis imminent. There are warnings of gales in all areas except Westminter, where disruption is expected. Soon.”

The protest comes as Brighton hosts the Labour Party conference.

Alison Plaumer, Extinction Rebellion activist, said: “With this action we are reaching out to the Labour Party to make the climate crisis the number one concern at this conference.

“We want those at the helm to listen to the huge number of voices within its own ranks who’re as terrified as we are about the ongoing collapse of the ecosystems on which all life on Earth depends.

“Make no mistake, at the moment we’re headed towards extinction.

“We are at a crucial moment in human history. We face an unprecedented challenge and our only hope is to work together to overcome it.

“We are asking everyone, including all members of the Labour Party, to take to the streets in our next International Rebellion in London, starting on 7th October.

“We urge members of other political parties too – as well as local councils, faith groups, trade unions and every kind of community group you can think of – to do the same. This is about all of us.”

James Moulding, Extinction Rebellion and Labour activist, said: “Tens of thousands across the UK are now organising, in active rebellion, against the British government and its ecocidal policies.

“We’re here today to call on Labour Party activists to join the Rebellion, to join our movement. This is how we change everything, and we need everyone.”

A Sussex Police spokesman said at 12.48pm: “A259 seafront in #Brighton now flowing freely again.

“The protest has come to a halt in Old Steine and small bit of road just north of Palace Pier roundabout is blocked, but traffic is diverting around it and the rest of the city is unaffected. Likely to last into the afternoon.”