I believe they can use ferret rounds:plastic rounds with teargas in them.
Also, I'm watching this on the news right now, and my head is full of forget-what exactly happened that made all the brits throw their tea to the ground?
Do you want to know what happened?
A group of our armed officers shot and killed a man they had been tailing for quite awhile.
I don't know the exact details, but he was on a list of bad people so it must have been quite official.
Our police force doesn't mess around, the problem is they can't take anti-riot action without permission from parliament, which means that our badass police-force which employ rugby tackles as a correct take down tactic can't do much at all when it really matters