According to the latest press-release from Paddy Power anyway:
(02 May 2011) Paddy Power have today paid out £15,000 to punters who backed next Thursday’s referendum on electoral reform to be rejected. The odds on a negative outcome tumbled from 10/11 at the end of February to 1/16 at the time of the bookies payout today.
Ken Robertson from Paddy Power said “From a betting point of view the writing has been on the wall for the A.V. issue for the past couple of weeks with 90% of all bets placed supporting the referendum to be rejected.”
Paddy is still however offering odds on voter turnout- 35.01% to 40% is the current favourite at 6/4.