I believe the process varies by CCG.
However, as all my GP knows about my diabetes is what is in the letter my consultant writes, I have absolutely no confidence my GP would understand the value a Libre would provide.
As with everything diabetes related, if you have type 1, I would encourage you to get to know your diabetes consultant or DSN. Given, as people with type 1 diabetes, we are less than 10% of the people with diabetes that are seen by GP surgeries, it make sense that type 1 is considered a specialism rather than something for a General Practitioner.
And, to my knowledge (but I am happy to be proven wrong), Libre are only avaialble on the NHS for people with type 1 diabetes.
I recommend being prepared with justification and evidence why you would benefit from a Libre as the estimate is only about 20% of people with diabetes will qualify.