The changes David Cameron has negotiated in the EU are "largely irrelevant to the problems most British people face", Jeremy Corbyn has said.
The Labour leader said Britain's relationship with the EU was a "sideshow" to the Prime Minister appeasing "opponents in the Conservative Party".
Mr Corbyn said Labour would be campaigning for Britain to remain in the EU because "it brings investment, jobs and protection for British workers and consumers".
He said: "Despite the fanfare, the deal that David Cameron has made in Brussels on Britain’s relationship with the EU is a sideshow, and the changes he has negotiated are largely irrelevant to the problems most British people face and the decision we must now make.
"Labour’s priorities for reform in the EU would be different, and David Cameron’s deal is a missed opportunity to make the real changes we need."
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.