Ex-London Mayor is campaigning for a "Leave" vote.
In an open letter, nearly 1,300 executives have backed Britain staying in the EU.
The stars are exerting their influence on both sides of Britain's EU referendum debate.
A poll shows many voters think the government is working with MI5 to rig the referendum.
Human rights and stability are secured through a union of states working together, however clumsily.
"Remain" and "Leave" campaigns pick up after death of MP Jo Cox as polls still show a sharply split electorate.
The EU Council President warned that if the U.K. voted to leave it could destroy the EU and make everyone worse off.
"You would have to start cutting things that people really value, whether it is the money going to the NHS or whether it is support for our pension system," prime minister says.
Lewis ranks among Britain's most trusted figures on the Europe issue.
Some recent stats have worried pro-EU campaigners, but there's no evidence they're behind.
Changes to voter registration and turnout issues have campaigners working to sway the young.
'Independent studies show that a vote to leave would hit the value of the pound, making imports more expensive and raising prices in the shops,' David Cameron says.
Forget the result; just having a referendum is causing uncertainty.