Let's vote again, like we did last summer

...around and around and around again.

First it was the Lib Dems demanding a second referendum - and look how popular that made them. Now it is Labour's Mr Khan saying, "we the people should take back control with a final vote on the [Brexit] deal."

Popular votes run on lies and misinformation, they are fuelled by emotion and rhetoric. As Clement Attlee said, a referendum is a "device of dictators and demagogues". Now this is as liable to being misunderstood and misapplied as Samuel Johnson's "patriotism is the last refuge of the scoundrel". The point is that both patriotism and popular votes are easily abused.

Mr Khan would be suggesting a very sensible, very democratic option if circumstances and the issue were different. The issue could be complex and controversial, the only requirement is that most people have an opinion about it, and that the decision they are making and the grounds they are making it on are crystal clear. It doesn't even have to be a yes/no decision. For example a vote on the latest date abortion should be allowed would be a proper use of a referendum.

So why not a yes/no vote on accepting a Brexit deal? Because the grounds for choosing are so unclear. A large proportion of Leavers simply wanted to reduce immigration, many others wanted more money for the NHS - the Leave campaign promised both of these things in order to win votes but then, once the votes were in, denied they had ever promised such things, telling us there won't be any more money and that immigrants will keep on arriving.

They lied and got away with it because it was so easy to do. The issues are incredibly complex, interdependent and long-term. Boris Johnson can still wheel out the "£350 million for the NHS" lie because on the surface it feels right - leave the EU and surely we save the money we currently send to them? If you take the time to go through the detailed facts and their consequences you find the money is no more than a mirage, in the same way that I could say I "saved" £30 by not buying a railcard.

The final deal will be far more complex than a railcard. The costs and benefits will only be reckoned over many years. So we will once again be at the mercy of single-issue voters swayed by fact-lite rhetoric. Ordinary people won't take the time to work through the details, even if they were given them truthfully - and fair enough that is what MPs are employed for. Some people may try to reckon it up, but how many will have the moral courage to switch their vote?

We don't need another referendum, we need a clear plan for the future, we need concrete aims that our politicians will honour. Good deal, bad deal or no deal, we will survive Brexit, but until we know where we headed and what we are prepared to sacrifice we cannot make a success of it.