The EU referendum will be "one of the biggest decisions this country will face in our lifetimes", David Cameron has said.
Following a Cabinet meeting, the Prime Minister said the Government position would be to remain in a reformed EU.
He said Cabinet ministers would be free to campaign on either side of the debate and that there would be "many passionate arguments".
"We are approaching one of the biggest decisions this country will face in our lifetimes," Mr Cameron said outside Number 10. "The choice goes to the heart of the kind of country we want to be and the future we want for our children.
"The choice is in your hands, but my recommendation is clear: I believe that Britain will be safer, stronger and better off in a reformed European Union."
David Cameron has warned that Britain has "100 days to secure our future", as a poll suggests the final result hangs in the balance.
The EU referendum is a choice between "the devil and the deep blue sea", one of the UK's most senior business leaders is to say today.
Britain's car industry is an economic success story, and with uncertainty over the impact of Brexit, it wants to stay put.