Thanks to @danielhowdon for spotting that they've published the underlying data for the weekly case (pillar 1 & 2) regional graphic in the surveillance report. That means we can look at the data in a more simple / comparative way. E.g.

Not saying these numbers are correct (usual potential problems around different levels of testing per region, duplicate tests etc.) but you can definitely see why they're focusing on Leicester. Here the full list of 150 split into 2 sections:

For reference, this is how the data is presented in the surveillance report. I prefer the simpler list view though.

As Daniel also says, this data can be used to extrapolate actual pillar 2 numbers by using known p1 values and population sizes. I quite like it in 100K form though as it's better for comparison. https://twitter.com/danielhowdon/status/1278060940953559043?s=20

So this shows PHE are prepared to release P2 regional case data in some forms. I just wish they'd do it on a daily basis and by specimen date like P1. Incidentally isn't York (my local city) meant to be on the hot-list? I make it as position 60/150, putting it in light-green.