Hi, you can also try the Pole Dancing School of Elena Gibson: http://www.poledancingschool.com/
They have several locations in London and do have drop-in classes. Check their website for locations and schedule.
Still living in the Netherlands by that time, I’ve tried one of these drop-in classes more than a year ago and I was amazed of the level of the girls & how professional the class was. The only minor thing for me was that they had 50mm poles and my hands were not used to that, so it was hard working.
Enjoy London!