So much has been said and written about the various Mid Term Review (MTR) options still to be decided for the Common Agricultural Policy (CAP), that many people have lost sight of two fundamental issues.

Firstly, this is not just a review, it is a revolution in the way support for farming is delivered by Europe. The word "review" suggests that a few Brussels Eurocrats have decided to make some minor adjustments to the existing CAP. They have not. This is root and branch reform of a hopelessly overloaded structure. It will impact on every farmer in the EU. But its longer-term effects cannot be predicted - largely because it changes the ground rules of the CAP

What ground rules? In essence, the link between production and support is being broken - or "decoupled" in the current EU jargon. That much we do know. What we don't yet know is how this new-style subsidy "cake" is going to be shared out. The portion each farmer receives will either be based on the subsidy claims that he made in the years 2000 - 2003 (the "Historic Option") or simply be a set amount paid on every acre of farmland in the country (the "Average Option").

There is now even talk of DEFRA choosing a mixture of these two options - known as the "Hybrid Option". This could yet become a very strange and complicated cake indeed!

So, whether we go for the Historic, the Average or even the Hybrid Option, there are bound to be winners and losers in this process, and its impact on some individual farmers looks likely to seem harsh. That is what happens when you suddenly switch from one payment system to another.

Second fundamental - why is this all happening? The EU often seems to find change very difficult - witness the recent collapse of the long-running negotiations over its new constitution. In complete contrast, the key elements of the MTR were pushed through very rapidly this summer. It is a done deal. All that is being done now is debating the finer (but crucial) details.

Why the haste? It all comes down to money - the CAP would have run out of it very rapidly if something drastic had not been done before Poland and the other new members join up to the EU. To have kept subsidies linked to production would have blown the budget sky high. Decoupling has allowed the level of farm support to be capped in absolute terms, however much or little farmers decide to produce in future.

This means that, over a period of eight years or so, farmers will get progressively less and less in the shape of "support-without-strings-attached". That is what the phrases "financial discipline" and "modulation" are all about. In future, what money there is in the system will increasingly be channelled into environmental schemes and structural reforms.

Global politics have also hastened this reform. The MTR puts the EU in a much better negotiating position for the next round of the World Trade Organisation talks. This combination of political and economic imperatives has meant that the difficult decisions had to be taken quickly.

Why should farmers concern themselves with these fundamentals, before they get too bogged down in the detail? Basically, because they must start planning now for a world without price subsidy.

In the meantime, farmers should avoid making any radical changes to their farming systems or structures between now and 2005, without first consulting an advisor who understands what is happening with the MTR.

We will not know precisely what needs to be done until DEFRA decide which MTR option to adopt.

One thing that farmers can do straight away is make sure they have accurate and complete records of their subsidy claim history from the year 2000 onwards, so that they at least have a firm foundation on which to base any decisions that need to be taken about the MTR in 2004/2005.