(Adds Reed, Farage)
By Elizabeth Piper
LONDON, Oct 11 (Reuters) - Campaigners for Britain to remainin the European Union will make a "patriotic case" that thecountry is safer in Europe, the group said on Sunday, bringingin business leaders, politicians and television personalities tolead the cause.
Called "Britain Stronger in Europe", the 'in' campaign willlaunch on Monday, keen to show it has broad appeal to fight forBritain's membership of the EU, the world's largest tradingbloc, before a referendum which Prime Minister David Cameronsaid will be held by the end of 2017.
Cameron conceded ground to Eurosceptics in his rulingConservatives by offering the referendum, hoping to bury anissue that divided the party for years, but the British publicis increasingly split over Europe, further complicating a votethat may cast a shadow over his last five years in power.
A day after naming Conservative peer Stuart Rose, formerboss of the Marks and Spencer store chain, as its head,the 'in' campaign said it would also be backed by fellowConservative peer, businesswoman and television personalityKarren Brady and Peter Mandelson, a former Labour minister andEuropean trade commissioner, among others.
"With backgrounds in security, culture, business, the youthmovement, trade unions, academia and politics, our board areready to make the case for why Britain is stronger, safer andbetter off in Europe," Will Straw, executive director of BritainStronger in Europe, said in a statement.
"We chose the name Britain Stronger in Europe because in thecoming referendum we will make a positive and patriotic casethat it is in Britain's interest to remain part of Europe."
Cameron has pledged to renegotiate Britain's relationshipwith the EU to get "the best of both worlds" by asking forguarantees the country will be kept out of ever-closer union andthat the euro is not the EU's official currency, protecting thepound in a multi-currency union.
He personally favours Britain staying in a reformed EU, buthas said he would not be heartbroken to leave.
Opinion polls are increasingly split over whether the publicwants to stay or not, with the migration crisis in Europespurring fears about open borders with the 28-member bloc.
'Britain Stronger in Europe' will argue that the countrywould lose its most profitable market if it left the EU.
"Forty-four percent of what this country exports goes to theEU ... the EU's the biggest game in town," said Richard Reed,co-founder of the Innocent smoothie brand and part of the 'in'campaign. "Let's not poke that big customer in the eye."
The main campaign to leave the European Union, called 'VoteLeave', launched on Thursday, drawing together politicians fromthe ruling Conservatives and opposition Labour party, andbusiness leaders such as billionaire hedge fund manager CrispinOdey.
But 'out' campaigners are split, with Vote Leave competingwith rival campaign, Leave.EU, backed by the Eurosceptic anti-EUUnited Kingdom Independence Party (UKIP).
For many Eurosceptics, the renegotiation is a waste of time.
Nigel Farage, head of UKIP, told Sky News Cameron's demandsof the European Union "amount to nothing". (Reporting by Elizabeth Piper; Editing by Janet Lawrence)
Marks & Spencer (MKS)