It has been noted that rumours have been doing the rounds at least 3 years and that nobody has backed them up. This may well be because people in the CAA and DfT are asking questions and thinking about the issue but have not yet formulated a firm view. My experience from contact with the CAA and DfT is that they can take time to address some issues. Take alcohol limits and police testing powers. These were first recommended by the AAIB in about 1991. The DfT issued a consultation paper on proposals in 1996 and legislation was made in 2003. That legislation will not come into effect until later this year.
Questions are also raised as to motive. I think the answer that is clear if you think about it. The Government is responsible the safety of aviation in the UK. Through Parliament it has established a regulatory regime and given the CAA the function of regulation aviation safety standards. By keeping and operating a foreign registered aircraft in the UK the provisions established by Parliament for the good of the population of the UK as a whole are being bypassed and responsibility is in effect being delegated to the authorities of another country. While the difficulties this could cause may be ignored if the number of aircraft involved is limited, it becomes more difficult for them to ignore if the scale of foreign aircraft operation rises. I have heard suggestions that getting on for 10% of privately operated aircraft based in the UK are on foreign registers, mainly the US, Bermuda and Cayman. The percentage appears to be a lot higher in respect of twin turbine powered aircraft.
If the CAA or DfT were to decide to do something about this, I am told the most obvious solution would be to follow the Canadian requirements which automatically grounds foreign registered privately operated aircraft if they have been Canada for more than 90 days in the preceding 12 months.
It is my understanding that the FAA, at a technical level at least, would be fully supportive of such action.