Members of Parliament are not our delegates. We elect them in order to make responsible decisions on our behalf, but not necessarily according to the wishes of the masses. The concept is that we give them, hopefully, full-time jobs in which they will become far more expert in matters of running the country than we are. We don't impose conditionality on them when we elect them. They have free rein, subject only to such things as party whips. If we don't like what they do, or think that someone else can do a better job, or if we think they are not paying sufficient regard to the concerns of their constituents, we can boot them out.

With regard to the referendum, Iain, MPs are not accountable for the popular vote (your expression). The referendum was advisory only. It was undemocratic for Cameron to make promises about implementation that were illegal. "Advisory" means that MPs may take into consideration what 38% of the electorate asked them to do ("asked" being the operative word). But it does not mean that they have to carry it out. I suspect that most of them will, but, if they don't, make no mistake - they won't have done anything illegal or unconstitutional. They will, of course, have to answer to their constituents.