The Prime Minister made the historic announcement in Downing Street after briefing the cabinet.
Speaking outside Downing Street, Mr Cameron warned that leaving the EU would be a “leap in the dark” as he urged voters to back his reforms and he described the vote as one of the biggest decisions “in our lifetimes.”
Mr Cameron confirmed the Cabinet had backed his plan but individual ministers would be free to campaign on either side.
Following his return from a marathon EU negotiating session in Brussels, the Prime Minister said leaving would threaten Britain’s “economic and national security.”
Mr Cameron said, “Those who want to leave Europe cannot tell you if British businesses would be able to access Europe’s free trade single market, or if working people’s jobs are safe, or how much prices would rise. All they’re offering is a risk at a time of uncertainty – a leap in the dark.”
Key elements of the deal include agreements over welfare payments to migrants, Britain’s right to opt-out of the Eurozone, and a promise the UK would have stronger sovereign control over laws made in Brussels.