One of the best examples so far of journalists’s use of the new Freedom of Information Act — the release of data on who specifically benefits from farm subsidies the EU Common Agricultural Policy &nmdash; also nicely illustrates one of the biggest problems with the open government laws: the clash of principles with the Data Protection Act.

The Guardian submitted its request in the first days of January after the FOIA came into force. Within hours of the request, the farming minister, Lord Whitty, told farmers at an Oxford conference that they should expect the CAP data to be released.

Farmers’ groups objected and a threatened injunction, arguing that disclosure would violate data protection principles and the individual farmers’s privacy. Rejecting these claims, the Rural Payments Agency in the Department for Environment, Food and Rural Affairs (Defra) released an Excel spreadsheet of CAP payments to farmers in England in March.

We learned for the first time that the sugar giant Tate & Lyle is England’s biggest single benefitiaries of CAP subsidies and that some of Britain’s wealthiest people, including the Royal Family, were collecting bucketloads of EU farm subsidies.

What we didn’t learn was anything about which Welsh or Scottish farmers were benefiting from EU subsidies. That’s because CAP payments are a devolved matter, and the responsible agencies in both the Welsh Assembly Executive and the Scottish Executive decided that releasing the data was exempt because releasing farmers’ names would be a violation of the Data Protection Act.

Data Protection is just one of more than 200 laws that bar disclosure under the new freedom of information laws. Navigating through this legal thicket is more or less up to the discretion of the agency that has recieved the request for information under open government laws, so it’s no real surprise that different agencies have come to different conclusions on the same complicated question.

(Politics may also have played a part. With the central government eager to discredit the CAP as part of its position on both the EU budget and international trade and development, ot would have had its own reasons for favouring disclosure — which may explain Lord Whitty’s enthusiastic response and may have some part in explaining why the central government agency responsible for England took a more liberal view on disclosure than its Scottish and Welsh counterparts.)

According to the BBC, though, one Welsh MP, Paul Flynn, has complained to the Information Commissioner about the non-disclosure of Welsh cap data. Flynn is who is now looking into the matter for a report he is preparing for a committee of the Council of Europe that compares CAP payments in England and Wales. So we may soon have some sort of resolution of this anomaly in the form of a decision notice from the Information Commissioner.