The campaign to avoid a Brexit and keep the UK within the European Union (EU) was launched with a band of business celebrities, including Virgin founder Sir Richard Branson and The Apprentice's Baroness Karren Brady. The pro-Brussels group, Britain Stronger in Europe, is headed by former Marks & Spencer boss Stuart Rose and run by Labour activist Will Straw.

The star-studded campaign was kicked off by TV presenter June Sarpong and Rose on 12 October at an event in East London. "People that know me will know that I'm not an uncritical fan of the EU," Rose said "But wanting reform is completely different, in my view, to wanting to leave. I believe that we are stronger, we are better off and we are safer within the EU than we are on our own."

The former business leader added: "We are fighting this campaign because we believe it is in our national interest to stay inside Europe. For centuries Britain has been a powerful trading nation, with a dynamic economy, and has been at the centre of world affairs and a leader in Europe. That's how we became strong, that's how we became proud, and that's how we became prosperous.

"That's why the choice facing us in this referendum is the biggest choice that we have had for perhaps a generation. Do we remain part of the largest free trade market on the planet? Or do we walk away, perhaps risking jobs and creating uncertainty in our economy?"

EU referendum: Stuart Rose launches campaign for UK to remain in EU [Video] IBTimes UK

The comments coincided with publication of the group's YouTube advertisement, which also features EasyJet boss Carolyn McCall and Universities UK chief Dame Julia Goodfellow. The campaign has also been able to sign up the three living former prime ministers − Sir John Major, Tony Blair and Gordon Brown.

The Brexit camps

The group is up against the two main Brexit campaigns, Vote Leave and Leave.EU. The former has the backing of Nigel Farage and his Ukip party, as well as being backed by Ukip donor Arron Banks. The other Eurosceptic group is ran by lobbying expert Matthew Elliot and has the support of Labour donor John Mills, Conservative donor Peter Cruddas and Phones4U founder John Caudwell.

The organisations are both competing for the official "leave" campaign nomination from the Electoral Commission, which will give the victorious group access to public money. Meanwhile, Mills has blasted David Cameron's renegotiation with Brussels.

The Labour donor described Cameron's talks as a "timid tragedy", in an exclusive article for IBTimes UK. "The tragedy as I see it is that by being so timid in our current renegotiation stance, we are throwing away a huge opportunity which would benefit everyone," the businessman argued. "I believe not only that it is in the UK's interest for our relationship with the EU to be re-forged, but it would also be very much to the benefit of the other EU member states for this to happen."

The EU campaigns may have launched, but it could be two years before the historic vote is held as Cameron promised to hold the referendum before the end of 2017. The prime minister is expected to back the "Remain" campaign, but is still seeking to negotiate concessions from Brussels.