so, when do you have the right to use force to stop an anti-abortion protestor?

when they stand in your way - and not before then.

talk is cheap, and the right to expression has to be much, much wider than telford & joly are allowing for.

these are arguably even abuses of power that necessitate some resignations; i haven't looked into it closely enough, but it's certainly straddling a line on acceptable behaviour from a cabinet minister, anyways.