OTTAWA -- An Ottawa-based think tank is backtracking after telling potential backers they could have a private cocktail with the prime minister if they paid the top sponsorship amount for an event next month.

The Macdonald-Laurier Institute posted a package on its website, which has since been changed, offering a one-hour private reception with MPs for the top sponsor of its Feb. 16 Confederation Dinner, a black-tie event to be held at the Museum of History. The "presenting sponsor" would provide $15,000 in return for a range of benefits, including a private reception featuring the evening's guest speakers -- and the prime minister.

The sponsorship package noted the prime minister's attendance at the event hadn't been confirmed.

A spokesman for Prime Minister Justin Trudeau said they hadn't received an invitation to the dinner, nor had they been contacted to attend the reception.

The sponsorship offer comes amid controversy over so-called cash-for-access events, at which Trudeau and some of his ministers have appeared at fundraising events with stakeholders who have an interest in lobbying the government.

CTV News confirmed Friday that Trudeau will instruct Democratic Institutions Minister Karina Gould to introduce legislation intended to make the fundraisers more public by advertising them in advance and allowing journalists to attend. They would also have to be reported publicly following the event.

A spokesman for the Macdonald-Laurier Institute said the information in the sponsorship package was an error, which was corrected after CTVNews.ca contacted him, since the prime minister would not be attending the event. Pressed on whether the sponsorship would have been offered if Trudeau were attending, the spokesman said no.

"We would not have included a private cocktail with the current prime minister as part of any sponsorship," Mark Brownlee wrote Wednesday in an email to CTVNews.ca.

But the event organizer said she included the offer of the cocktail with Trudeau at the request of the institute.

"This was not something that I would have suggested to them," Connie Lebrun said in an interview with CTVNews.ca.

"As somebody contracted in to run the logistics of [an] event, they're my client, so I really can't speak to that."

In a follow-up conversation, the institute's director of communications said an early plan for the dinner had been to invite former prime ministers, but "there are no plans to have the prime minister there or have anyone have access to him."

"I suppose someone in the marketing department thought it was a good idea, but it doesn't reflect anything that's planned for the dinner," David Watson said in an interview Friday.

"No one at MLI has been in touch with [the Prime Minister's Office].... It was an error to put that in the program. I don't know actually how it originated, but it's not the kind of thing that we would do."

The $15,000 sponsorship, the top level offered by the institute, hasn't been sold, Watson noted, and the error has been removed.

One of the lower-level event sponsors is Lockheed Martin, which lobbies the federal government on a range of defence procurement issues, notably on shipbuilding and aircraft acquisition. Lockheed Martin produces the F-35 fighter jet.

Lockheed Martin's sponsorship level, $7,500, isn't enough to have received access to the private cocktail party.

The Macdonald-Laurier Institute offers experts and commentary on subjects including foreign affairs and defence, public safety and social issues.

With files from CTV News Channel’s Michel Boyer