How has the EU reacted to Cameron's reform demands?
Prime Minister David Cameron has published a letter outlining his four main issues for reforming the UK's membership of the EU.
The list of goals - the single market, sovereignty, competitiveness and immigration - was branded a gimmick by some Conservative colleagues.
The European Commission claimed some parts were "highly problematic".
So how have EU member states reacted to the demands?
Europe editor Katya Adler reports.