Toronto Mayor David Miller endorsed mayoral hopeful Joe Pantalone on Wednesday. (CBC)

Expressing his "frustration and distress" with the race to replace him, Toronto Mayor David Miller has finally endorsed one of the candidates.

In short speech at a cultural centre in Scarborough, Miller announced his "support and endorsement for the next mayor of Toronto, Joe Pantalone."

Pantalone has been the deputy mayor of Toronto for the past seven years and entered the race to replace his boss in the spring.

But until now Miller has refused to back a specific candidate in the Oct. 25 vote.

On Wednesday, Miller made it clear why he had chosen to come out now.

"Like many Torontonians I've watched this mayoral race with incredible frustration and distress, because what I've seen is candidates that want to tear this city down," Miller said.

"The last few weeks Torontonians in every neighbourhood ... have been telling me that they feel the same way I do, that they're appalled by the level of debate in this mayoralty and they want someone to lead this city who's going to build a great 21st century city for themselves and their families."

Miller didn't mention the other leading candidates by name, but his remarks appear to have been directed at Pantalone's main challengers, Rocco Rossi, George Smitherman and Rob Ford.

Earlier on Wednesday veteran city councillor Joe Mihevc announced he is supporting Smitherman.

Mihevc encouraged Torontonians to vote for Smitherman to keep fellow councillor Rob Ford from winning.