Anything weed related in England is fairly well tolerated.

I've rolled joints in taxis before, i've walked around in central London smoking before, i've driven past cop cars with my windows open smoking, and i've bough weed openly in the street.

Infact, weed was even legalised for a period of time in south London.

At night, if you drive around the right parts of London the smell of skunk is in the air.

So yeah, in England you can get away with it 99% of the time, and that's no exageration. If you are unlucky enough to get an arsehole copper all they'll do is throw the weed away and that'll be it.