If David Cameron makes his renegotiation plan public – assuming that there is one at this stage – some of his Ministers, many of his MPs, a lot of party members and a big slice of Party members will demand more. And by doing so, he would also tip off those in other EU countries and institutions that are opposed to any repatriation of powers in any event.

But if he doesn’t, he risks allowing the Leave campaigns to make the running. This is precisely what has happened to date – which is why he warned against leaving the EU last week, a position that he himself hasn’t ruled out supporting.

The complexity and tortuousness of this position may be having an effect on public opinion. Over at UK Polling Report, Anthony Wells notes that a recent YouGov poll found Remain and Leave at 50 per cent/50 per cent, though the regular ICM tracker is in its own words “fairly stable”, with Remain at 54 per cent and Leave at 46 per cent.

At any rate, it may have moved our own survey. Last month, 66 per cent of respondents said that they are more likely to vote to Leave than Remain, and 30 per cent the opposite. This month, those figures are 71 per cent and 24 per cent respectively.

That was the first time we had asked a question that takes the renegotiation into account. In June, a straight choice between remaining or leaving had produced 30 per cent for staying and 58 per cent for leaving.

In this survey, 19 per cent of all website respondents were for staying and 77 per cent of all website respondents were for leaving. We got 761 Party member responses to the poll out of a total of 1756 replies.