THE litmus test for a really sound deal is that it leaves both parties vaguely dissatisfied.

I am delighted that we have completed the tortuous phase one of the Brexit negotiations (and welcome the fact that we got at least some concessions from the Europeans).

Phase two should be a great deal easier, not least because the European countries know very well that they need tariff-free trade with the UK more than we need it with them. Theresa May must be ready to pay hard ball with them to remind them of that sheer economic reality.

I feel perfectly happy about the mutual arrangements for EU and UK citizens, which is entirely logical. The continuing role for the European Court of Justice for eight years may be a symbolic blow for the Remainers. But it is at the discretion of British judges and will be used in only a very few marginal cases where UK law cannot decide what is right for EU citizens in the UK.

The £39 billion price, of course, is huge. But it will be paid over a very long period, and the £13 billion net which we pay to the EU today will quickly gobble it up. And I welcome the absence of any ‘hard border’ with Eire, which would anyhow have been wholly impractical. So far so good.

But I am concerned by the meaning, effectiveness and long-term consequences of the ‘regulatory equivalence’ which was necessary to achieve the Northern Irish solution. If it means, as some have interpreted it, that we will forever accept EU regulations, then we are in effect remaining members of the Single Market and Customs Union.

It would mean that we cannot do trade deals with other countries, especially the US, whose regulations may well be wildly at variance of the EU ones.

It is pointed out that Japan, Korea and Canada have all equally agreed ‘regulatory equivalence’ in order to achieve a trade deal with the EU, and that does give me some comfort. But I remain uneasy about it.

It is surely obvious that if you want to sell goods or services to another country, or group of countries, then quite plainly the standard to which they are manufactured must match those of the buying country. If they do not, you will not be allowed to trade with that country.

We will not allow sub-standard goods from other countries to undercut our own goods manufactured to high British regulatory standards. That applies whether you are selling to the EU, Australia, America or India. And it is largely a matter for businesses to ensure that their product meets the high standards of the country to which they are selling. But that should not be a matter for international treaties and governmental agreements, so much as sound commercial common sense.

So I welcome the progress so far, and I congratulate the PM on achieving it. But I am watching it all very carefully indeed and am by no means giving the deal my unconditional support. It’s a bit of a fudge in some respects (as all good deals probably are), and there are some very worrying elements to it. But for now I will give it the benefit of the doubt.

So for now it's back through snow, storms and floods to Westminster after a positive blizzard of constituency events, all of them thoroughly jolly, to a final marathon getting the Brexit Bill through its committee stages. (Midnight votes all week by the look of it.) By the time you read this l will truly be looking forward to a Brexit-free Christmas holiday.