I don't wait to be given a chance, I make the decision about when to rejoin the flow of traffic. When the queue starts moving again, wait until the car 2 or 3 ahead starts moving and pick the gap you are going to take. Slow down and get into a good gear to accelerate again, take position next to 'your' gap as the traffic moves off then move left when your speeds are matched. It is not the driver's choice.
This does, as Andrew Culture alludes to, need confidence and practice, but I use it three or four times daily, even on my relatively short commute, and it works well. I think it helps that many now recognise that I'll get into town faster than them anyway, although that does loop back in a geometrically pleasing fashion to the subject of this thread.