Listen to this articleEstimated 3 minutesThe audio version of this article is generated by AI-based technology. Mispronunciations can occur. We are working with our partners to continually review and improve the results.A Mainstreet Research survey released Friday puts Olivia Chow, centre, at the head of the pack by six points with 38.1 per cent support. Brad Bradford, left, is in second place with 32.