British Prime Minister David Cameron reacts as he travels on his campaign bus from Bristol, Britain on June 22, 2016. [Photo/Agencies]

REMAIN—Britain stronger in Europe

* David Cameron (UK Prime Minister)

"Britain will be worse off if we left" and "a permanently poorer country in every sense," Cameron warns.

* Sadiq Khan (London Mayor)

Leaving the EU would be a betrayal of British values and send a message to the world that the country wants to stand alone, Khan has said.

* Nicola Sturgeon (Scotland's first minister)

Remain vote was the "only sensible and logical" course for those who want a re-run of the 2014 poll, the First Minister says.

* Richard Branson (Entrepreneur)

"Brexit would deal a devastating blow to the UK's economy" and it is "not a risk I would want to take. Not as an investor, not as an entrepreneur," the Virgin Group boss says.

* David Beckham (Former English footballer)

Beckham believes a "vibrant and connected world where together as a people we are strong", and wants his four children to grow up "facing the problems of the world together and not alone."

* Stephen Hawking (Physicist)

"By working together in Europe we make our economy stronger and we give ourselves more influence in the world and we provide future opportunities for young people."

* Benedict Cumberbatch (Actor), Jude Law (Actor), Keira Knightley (Actress)

"We believe being part of the EU bolsters Britain's leading role on the world stage. Let's not become an outsider shouting from the wings," three leading British actors and nearly 300 other artists, actors and musicians caution.