It is very hard to imagine what better deal for UK´s EU membership David Cameron could achieve that would help him to win an in-referendum at home. That is at least the sobering result of a simulated European Council meeting where 14 experts from renowned European think tanks slipped into the role of their respective heads of state or government and negotiated with the UK of what is thus far known to be the British demands.
The simulation showed that even if his EU colleagues are willing to lend him a helping hand there is not so much they can do for him because treaty change is out of reach in the time left, and on top the length of the EU legislative procedures will evenly not produce many tangible results in the realm of deepening the single market until the end of 2017.
Cameron might have to become much more realistic as well as constructive in what he will be asking for in his letter to the Council promised for early November. On top, it seems advisable that he changes his role from sole demander to a leading reformer and makes himself the spearhead of an all-out treaty reform. Getting the other member states to agree on a date for a European Convention seems more convincing than legally non-binding declarations that the UK will receive for example its opt-out from the ever closer union if and when sometime in the future treaty change is taken on.
You can look up the results of the simulated EUCO here. The commentary is the first offspring of a joint project of the Centre for European Policy Studies and the Bertelsmann Stiftung.