Mayor Larry O'Brien invited some Ottawa councillors to a special meeting Tuesday that may have broken a provincial law, says a councillor who wasn't invited.

After the meeting, 13 councillors stood behind the mayor as he held a news conference about the city's fiscal future, referred to some of the financial topics that he discussed with them and praised them for their support.

When questioned by reporters, O'Brien later admitted that only a select group had been invited to the meeting. Ottawa council has 23 members, plus the mayor.

"This particular group of councillors are ones who have provided me with support through an obviously difficult time. They're not scurrying off in the back rooms trying to promote plan B and I think that's worthy of me buying them a coffee and a donut," he said.

The mayor appeared to be referring to plans for what might happen if he should be charged in relation to an Ontario Provincial Police investigation into allegations that he tried to bribe rival Terry Kilrea into dropping out of last fall's mayoral race.

But Bay ward Coun. Alex Cullen, who wasn't invited to the mayor's meeting, said he had concerns that the meeting may have contravened Ontario's Municipal Act, which states that meetings attended by a majority of council members must be open to the public.

"Those kinds of meetings are not encouraged, not recommended by legal staff," Cullen said.

O'Brien said the gathering was an informal one, not a meeting, and he has no regrets about it.

Alleged violations of the Municipal Act are only investigated if someone lodges a formal complaint. Cullen said he is not planning to lodge such a complaint.