The Tories can change anything they want on a whim.
I don't actually believe this as we've already heard Tory Cabinet Ministers saying they have been prevented from doing things they wanted to, for instance road safety measures that came into conflict with EU rules
but
Don't think that Labour will be able to change what they want to do on a whim. Things like renationalisation of railways and public subsidy of the steel sector are prohibited by the EU. Will we then finally hear some Labour moans about the EU 'stopping is doing what we want'?
This is not a pink and fluffy EU that has the welfare of its citizens uppermost. It is a brutal organisation that has treated Greek ruthlessly and has dithered and prevaricated as millions of refugees and migrants have rushed to Europe.
One day it might be a very right-wing organisation. The right-wing is rising in EU member countries. If these parties eventually become national Governments they will be sending their right-wing politicians to Brussels. Are you prepared to be controlled by a Europe-wide hard right organisation? Because if you welcome what you perceive as the Left wing socialism of the EU tying Cameron's hands, you must also be prepared for the right-wing ultra-authoritarian EU one day that may tie Labour's hands. And you will be stuck with it.