Mayoral candidate George Smitherman tore into his rival Rob Ford on Wednesday over comments he made four years ago, when Ford said only gay people and drug users were at risk for contracting AIDS.

"I'd like you to explain to people how your character, and especially these comments, is justifiable now that you present yourself as someone who wishes to be mayor of Toronto, one of the most diverse places to be found anywhere in the world," said Smitherman, during a debate in front of Toronto Real Estate Board members.

In 2006, Ford argued against a $1.5-million AIDS prevention strategy, telling council: "It is very preventable. If you are not doing needles and you are not gay, you wouldn't get AIDS probably, that's the bottom line."

After Smitherman brought up the comments Wednesday, Ford did not respond. Instead, he mentioned his charity work.

"I have a Rob Ford football foundation. I'm caring. I help get these kids out of gangs," he said, before launching an attack of his own.

"You want to get personal, go ahead. I've got an agenda here and this is how the city is going to be run. I'm not going to play games like you have, blowing a billion dollars on eHealth," Ford said.

Smitherman was never minister responsible for eHealth, but he did preside over its predecessor -- the Smart Systems for Health Agency. Created under the previous Progressive Conservative government, the agency spent $650 million on developing online medical records. However, it made little progress.

Ford avoided the AIDS question a second time on stage and again during a scrum afterwards.

Smitherman, speaking to reporters after the debate, said the issue struck close to home.

"Of course, I'm a gay man so it's somewhat personal, isn't it," he said.

"You want to be the mayor of a city that says diversity is our strength, is our motto and you make comments that disparage gay people, people who are street involved and women for their conduct so as to suggest that it's not necessary in health prevention to matter about them. I just think that people need to understand, this is an important question that needs to be addressed."

A recent poll showed Ford running second behind Smitherman.

With a report from CTV Toronto's Alicia Markson