It is hard to believe it is two years since Boris Johnson and David Frost celebrated a Christmas Eve 'trade deal' with the EU.

This was proof to Johnson that his fantasy of an 'oven-ready' post- Brexit deal was possible. There was relief that it averted the prospect of a New Year drop off a cliff into World Trade Organisation trading rules and tariffs between the EU and UK.

The deal allowed Johnson and Frost to boast that they had indeed 'got Brexit done' on their terms. In reality, what emerged on that Christmas Eve was the least worse of two options.

The outcome, two years on, remains a fudged deal built around politics, rather than business interests.

Despite the deal's many flaws, trade in food and farming between the UK and EU has largely recovered to pre-Brexit levels. The UK continues to import more than it exports.

The deal has worked because business shouldered the costs and red tape to make it work as effectively as possible. The government has not engaged in making what it agreed and saw as a good outcome work for business.

It has failed to resolve, through negotiations with Brussels, the many issues that are creating problems – the most obvious example being the Northern Ireland Protocol.

To get Johnson the deal he wanted and the ability to boast about 'getting Brexit done' he knowingly split the UK by putting a border down the Irish Sea. This was always an ill-conceived decision that was going to come back to bite and it has, politically and economically.

The roots of this problem lie in a single decision by Johnson – his instruction to Frost and other negotiators that sovereignty must take precedence over concessions on market access.

This kept the UK out of the European Economic Area and most of the problems we now face flow from that decision. Matters have been made worse by the UK's inability to implement its own customs rules for imports from the EU, while by contrast EU member states had their systems up and running early in the new trade process.

The result is that Brexit has been largely meaningless in trade terms. It has not helped boost home demand, nor has it been a driver for trade deals beyond the EU.

On the surface everything is largely the same as before Brexit, but with some huge issues not tackled and with businesses carrying a costly red tape burden to continue supplying a market that was once their home market. These were raised recently in a trade forum in Brussels by the UK farm unions.

There are specific issues around the Protocol, including continuing access to veterinary medicines, but the EC has sought to resolve these in a practical way, while the UK is on the sidelines and fails to engage. The UK focus is on politics rather than practicalities, while Brussels seems to be tackling things the other way around.

A big issue that has not been resolved and which shows no signs of resolution, is the position of Scottish seed potatoes. The industry has lost valuable markets in Europe and specifically in Ireland, north and south.

Parallel standards are not accepted by Brussels, partly because these were not made a priority in negotiations on agriculture. There was an assumption common sense would prevail but that has not happened and there seems little cause for optimism a solution will be found.

Because Northern Ireland remains in the EU single market, Scottish seed cannot go there any more than it can go to the Republic of Ireland or any other EU member state. That is unfair and wrong, but fairness and politics rarely go together.

This reflects the focus on sovereignty and Scotland's potato industry is a casualty of that war between Brussels and London.

Come the new year farmers in the EU will have a new CAP. It is claimed to be much greener, but in reality it is not significantly different.

Crucially, it guarantees direct payments of around £260bn a year will continue. In uncertain times that is a great security blanket for farmers in the EU. The Johnson Brexit is a disappointment for farmers enthusiastic about the opportunities it would bring.

It has failed to deliver for UK agriculture in terms of productivity, global competitiveness or new market opportunities. In short, we have EU policies and green ambitions, but without the massive financial backstop of the CAP.