Addison Lee drivers told to defy bus lane law (and to just say SMIDSY)

Road positioning is a dynamic and often subtle thing; encouraging cyclists to take up one position at all times is the opposite of what Cycle Training is about.

All true yet as a protest which was widely publicised it would be less annoying for drivers than waiting for 20 minutes while the critical mass goes past. There would need for a huge build up and publicity about 'middle of the lane day' . We may have enough 'critical mass' of riders especially during the commute for it to succeed. And it could only work in London at the moment