I would assume if you get off your bike, lift it onto the pavement then push it past no problems, but pushing it over the stop line is a different matter. A copper would have to be extremely bored to even bother giving you a talking to.
A pedestrian is supposed to cross in between the studs marking the crossing, they should not be on any other part of the crossing.
Now, I am certain that pedestrians legally have Right of Way on all parts of the carriageway. So a pedestrian wheeling a bike does as well. Personally I'd rather wait at lights than dismount and wheel.