MONTREAL - An official in the Prime Minister's Office says Paul Martin is not at the closed-door North American Leaders' Summit in Montebello, Que.

During a Montreal news conference, federal NDP Leader Jack Layton appeared to say the former prime minister was part of an elite group of business leaders invited to the meeting.


But PMO spokeswoman Sandra Buckler said Monday that Martin is not attending and was not invited.

During the news conference, Layton said that Martin "was a member of the very group of CEO's that is the lead champion (of deeper integration with the U.S.) and has managed, by the way, to get inside the doors of the meeting.''

Layton said "not even the leaders of the other political parties are being invited to discuss it, even with our own prime minister."

The NDP leader later explained his comment as referring to Martin, before he became prime minister, being a member of a business group now called the Canadian Council of Chief Executives.

That group is a member of the North American Competiveness Council -- a group said to have access to the summit in Montebello.

Maude Barlow, of the Council of Canadians said the 30 business leaders who sit on the North American Competitiveness Council is made up of leaders from 10 companies in each country and advises the three national governments on facilitating trade.

Layton challenged Prime Minister Stephen Harper to release the list of business leaders who are at the summit with U.S. President George W. Bush and Mexican President Felipe Calderon.

The NDP leader was campaigning with Thomas Mulcair, the NDP's candidate for the Sept. 17 byelection in the Montreal riding of Outremont.

The former Quebec environment minister is running in one of three federal byelections which have been called by Harper.

Layton says he'll be spending the next few days working on improving his French and will not be joining protesters in Montebello.