EU Referendum

Moving this here from Makemakean's PM so that we can discuss it better.

Gentlemen,
In the establishing of our manifesto, I believe this issue can be the single hardest one to decide about. I won't deny that in my heart I yet remain a Europhile, but I have come to the conclusion that it has become indefensible to keep Britain in the EU without an actual mandate to do so. With now over 70% demanding a referendum in the polls, you can no longer deny that refusing the people a referendum is an obstruction of democracy.
To be concrete: The question is no longer if we should hold a referendum, but when.
Now, from reading AndyC's Ideal UK (in my opinion an excellent list of ideas), I see that our Shadow Chancellor outright wants to leave the EU. From this I can only infer that he wishes for a referendum to go ahead as soon as possible after the election. Personally, I am split, and would ideally like to put it at two years after the election (i.e., in 2014).
My reasoning is simple, at the moment I believe the Eurocrisis can yet reach some sort of stabilization within a year or so, and thus an immediate referendum, followed by a likely exit by the UK could inflict massive damage to the European economy, thus hurting the UK severely. In two years time, however, things would be different. To appeal to the LibDem Europhiles among us, if the seas of the European economy have finally flattened out and the storm has come to an end, then the Yes2Europe side is likely to win, and the EU has in some sense been vindicated as a project.
However, if the tempest of the markets is still raging, and the crisis has but gone worse, then I hope that you will agree with me that no intellectually honest person (not even the most devout Europhile) can any longer consider the EU project to be anything but a failure that must be brought to an end as soon as possible. I would say that in this situation, the ideal would be to apply for membership in the far more decentralized EFTA and work for it to replace the EU in the role of providing an open, common, European market.
Thus, I hereby send this question to you: When would you suggest is the best time to hold a referendum?
Best Wishes,Max.