Number 10 has got quite the job to do over the next few days if it is to get backbenchers ready for David Cameron's EU speech on Friday. Tory MPs are now obviously in a high state of excitement, but their expectations will inevitably be disappointed to some degree.
Some are already expressing fears about this, including the MP leading calls in parliament for a referendum. John Baron, who chairs the All-Party Parliamentary Group for an EU referendum, tells me that he is worried the 'mood music' in Europe isn't quite as positive about renegotiation as the Prime Minister might hope. He says:
'The chance of repatriating powers, I think they are slim: but I wish him well. I do wish him well because I think that we need to repatriate powers back to the UK, but the mood music is very different to what the Prime Minister is saying. They are not sympathetic to the idea of any states repatriating powers; if anything, the direction of travel is the other way.'
Baron also co-ordinated a letter signed by more than 100 Tory backbenchers calling for legislation in this parliament for a referendum in the next. The point of the legislation was that it would provide voters with as cast iron as cast iron guarantees can get that the government would definitely consult them on Britain's relationship with Europe.
'My view is that whatever promises the Prime Minister makes - and my hope is that there will be a referendum, he talked about asking for the consent of the British people - whatever promises he makes must be ones he can keep.'
Some MPs are also worried that the speech itself won't quite address the issues as clearly as backbenchers are hoping. One senior Tory MP warns darkly that 'another mañana moment will not cut the mustard', and that any failure to make a clear pledge will lead to backbenchers calling a vote in the Commons which would attract even more rebels than the 81 who called for a referendum in October 2011. Meanwhile, Conor Burns, who as a PPS wrote his own letter to the Prime Minister to accompany the Baron letter, says:
'There is a real danger in modern politics of following the example of Mr Blair in believing that when you have made a speech, something has happened. When you have made a speech, the only thing that has happened is you have made a speech. The speech is only the beginning of a process of renegotiation.'
Former children's minister Tim Loughton, a member of the Fresh Start Group, underlines the importance of that renegotiation. He and his colleagues will publish a list of proposals for renegotiation tomorrow. Loughton says:
'If we are quite clear that we are serious about renegotiation and fail to get it, clearly we should go to a referendum on our future membership overall, but the preference is for us to stay in a different sort of EU.'
Meanwhile Priti Patel warns that the speech 'must recognise that the British people recognise that there's a fundamental democratic deficit when it comes to Britain's relationship with the EU'.
Over the next three days, Downing Street, the Whips and ministerial PPSs should be taking outspoken MPs out for coffee and preparing the ground for the Cameron speech. This week is a test of how well the Whips and the Tory leadership can work in getting certain MPs to pull behind the PM. They will not be able to stop some of the usual suspects from being inconveniently outspoken, but there are others who could probably be persuaded to support the Prime Minister if they feel they are being listened to and are needed within the party. As I've blogged before, the party operation hasn't always been very impressive on this, but the next few days are some of the most critical of this Parliament for Conservative party unity.