In a post in this thread someone claims that this is the fix:

Turns out google have screwed up some (if not all) UK accounts with the switch to GMail.

The fix is simple. Change your account from @googlemail to @gmail, wait an hour (recommend 2) then factory reset your phone, sign into your google account (@gmail) and your good to go

You can change your account from @googlemail to @gmail in the GMail setting (On a desktop computer not a phone) The option is in tiny writing
Before I try this I wanted to ask: Is everyone having problems in the UK and do you all have @googlemail email addresses?