115 Undue influence.
(1)A person shall be guilty of a corrupt practice if he is guilty of undue influence.
(2)A person shall be guilty of undue influence—
(a)if he, directly or indirectly, by himself or by any other person on his behalf, makes use of or threatens to make use of any force, violence or restraint, or inflicts or threatens to inflict, by himself or by any other person, any temporal or spiritual injury, damage, harm or loss upon or against any person in order to induce or compel that person to vote or refrain from voting, or on account of that person having voted or refrained from voting;
The threat of a spiritual injury would include telling people that they risked eternal damnation if they vote for a certain candidate, or saying things like The people that don't vote for me will be weighed in the balance, come Judgement Day. The Archangel Gabriel will say, 'You didn't vote for Ken Livingstone in 2012. Oh dear, burn forever. Your skin flayed for all eternity'.
The comments might have been uttered in jest, but uttered they were and as we have seen recently only joking is no defence, so if I was a London supporter of Mr Johnston or any other mayoral candidate I might be very tempted to send a copy of the latest edition of Total Politics to Mr Plod at the Yard