Andrew Haydon, seen here in 1991, is the former regional chair for Ottawa-Carleton and the former mayor of Nepean. (CBC)

Andrew Haydon, a veteran of the Ottawa political scene, launched an unexpected political comeback on Friday, entering the race to become the city's mayor.

"I want to be your next mayor," Haydon, 76, announced on Friday morning.

Haydon, the former regional chair of Ottawa-Carleton and Nepean's first mayor, registered as a candidate on Friday, which was the last day for candidates in the Oct. 25 municipal election to register.

Haydon's last run at City Hall came in 2006 when he ran for council in the Gloucester-South Nepean ward and lost to Steve Desroches.

With Haydon's entry, the total number of candidates running for mayor is now 20, including incumbent Larry O'Brien, former pre-amalgamation Ottawa mayor Jim Watson and current Capital Ward councillor Clive Doucet.

There are now 110 candidates registered to run as councillors in the city's 23 wards, and there are 130 candidates for Ottawa city council.

'Why is age important?'

As he kicked off his campaign, Hayden also launched a pre-emptive strike over questions about his age.

"Why is age important?" he asked.

Hayden also attacked O'Brien, saying: "He came in without a business plan, that's been his problem from square one. He never had a grasp of how to operate a municipality."

"I think it's a little sad that he tries to go personal right away," O'Brien responded. "I welcome this gentleman from previous centuries," he added.

Candidates spar over transit plans

Haydon's platform includes trying to stop the city's light-rail plan and to focus instead on overhauling the bus system.

"Mr. Haydon and I disagree on the rail versus bus debate, but I've great admiration for Mr. Haydon," Watson said.

Doucet also questioned Haydon's transit plan.

"His idea of a busway under the city is right out of the dark ages. No one uses diesel fuelled buses in tunnels six storeys down."

Haydon served as reeve of Nepean township from 1970 to 1978 and was briefly the newly incorporated town's first mayor before serving as regional chair of Ottawa-Carleton from 1978 to 1991.