You can picture the scenario... JetA1 for "export" (i.e. international airlines) will remain the same, but any fuel used purely for within the UK (i.e. 99% of our domestic helicopter industry) will be taxed at the same rate as Avgas.... arrrrgggg
You got it in one, except that the UK government wants to see the end of tax free JetA1 globally. This is a tougher nut to crack than simply the domestic market - but that would be a start.
The background to my observation was a memo passed on to me about 2 years ago emanating from HM treasury addressing this issue and also the environmental 'implication' of tax free fuel.
Government's position is it does not like the idea of tax free fuel and wants to end it but ICAO rules are a big obstacle.
I'll see if I can find the note and post it up.