David Cameron's promise of a referendum on the UK's future membership of the European Union could create problems, Tony Blair has warned.

Mr Blair told presenter Sian Williams on the BBC's Andrew Marr Show that if "Britain did vote to go out it would be a huge problem for our country".

Mr Cameron has pledged to renegotiate the UK's membership of the EU and put the "better deal" he hopes to secure to a vote of the British people before the end of 2017.