Indeed. It gets better, though.
His firm has to use diesel-powered generators 24x7 on their sites to power pumping and filtering equipment as invariably there isn't grid power at the locations. In aggregate they burn around 3,000 litres of "red" diesel a week doing that, but as of 1st April they have to use "white" diesel due to changed government regulations, adding around £1,800 per week to their costs. Guess who's going to be paying for that (clue: it won't be his firm)?
IIRC this is to 'encourage' companies to move away from diesel power for emissions etc. reasons, although I'm not sure what alternatives are available/practical right now. I think red diesel use continues for agriculture ... it's mainly the construction industry that's being targeted. As a tractor owner I ought to know but I've used white diesel so far anyway as I don't get through much!