@Fairygodmother 's mention of the Equality Act reminds me that we had a solicitor come to our office a while back to do an inhouse seminar on the Equality Act and reasonable adjustments in the workplace.
I mentioned libre, how it made life easier and asked whether purchase of it by the employer would be regarded as a reasonable adjustment for T1 employees.
Surprisingly, he said yes. Obviously, it was just an off the cuff answer without being fully thought through, but it got me thinking that there might be a case for running it past HR.
If you're in a trade union, I wonder whether it might be worthwhile getting some advice from their lawyers.
Libre's great but having someone else paying for it is even better.