|I say, who let in those plebs?|
The suggestion that renegotiation of our relationship with the EU is possible is a con. There is no legal basis for a "pick n mix" membership and absolutely no appetite for it in the EU or the leaders of any of the EU member states. When superficial attempts to renegotiate fail the referendum will have produced an overwhelming "in" vote which will be held up as "proof" that the electorate want to stay in the EU.
There is also the little publicised fact recently revealed by Better Off Out that 2017 is the date specified in the Lisbon Treaty for mandatory full fiscal union for all EU member states. That means goodbye pound, hello €uro. With 2018 being suggested by Tory MPs as the most likely time for the aforementioned mythical referendum, leaving would then involve unpicking fiscal union and bringing back the pound possibly less than a year after it has been abolished.