What you need to know about why we didn't sign up!

Why did David Cameron refuse to sign up?

Before the summit, Mr Cameron said he would not sign up to any change involving all 27 member states that did not protect British interests - particularly on financial services and access to the single market. The UK has long been resisting calls from other EU leaders for a Europe-wide bank transactions tax which it says would hit the City of London hardest. It is not thought such a tax was specifically discussed but Mr Cameron sought a separate legally-binding "protocol" to protect the City of London from more EU financial regulations# He didn't get one# France's Nicolas Sarkozy argued that much of the financial crisis was down to a lack of regulation and it would not have been right to give the UK a "waiver"#

What else did the UK government demand?

Mr Cameron also wanted an agreement that the European Banking Authority would remain in London, protection for US financial institutions based in London that do not trade with the rest of Europe, and an agreement that any changes - including a financial transactions tax - would require the unanimous backing of all EU members# He didn't get any of those either#

Who is to blame?

French President Nicolas Sarkozy has laid the blame squarely at Mr Cameron's door. He says he would have preferred a deal involving the 27 EU states but that wasn't possible "thanks to our British friends". But the UK government says it was not asking for anything unreasonable. Foreign Secretary William Hague said EU leaders had made "nothing like enough of an effort" to meet UK concerns. Deputy PM Nick Clegg, whose Liberal Democrat party is much more pro-European than their Conservative coalition partners, said the UK's demands had been "modest" and affected the single market as a whole, not just the UK. Labour say the PM failed to build alliances in Europe ahead of the summit and has achieved nothing that will protect the City of London.

via www.bbc.co.uk