OTTAWA -- Justin Trudeau is launching a pre-emptive strike to prevent federal Liberals from using upcoming nomination contests to resume the toxic infighting that almost destroyed the party.

His team has informed Christine Innes that she will not be allowed to run for a Liberal nomination in any riding after receiving complaints that her husband -- former MP and junior cabinet minister Tony Ianno -- has been using "intimidation and bullying" in a bid to lure supporters away from newly elected star recruit Chrystia Freeland.

Barring Innes is intended to send a message to all Liberals, Ontario campaign co-chair David MacNaughton said in an interview.

"We're not going to go back to the days of the Hatfields and McCoys in the Liberal party."

MacNaughton informed Innes of the decision early Thursday morning, outlining the accusations against her campaign team.

"Derogatory remarks were made to several young, enthusiastic Liberals about one of our leading MPs. Suggestions were made to volunteers that their future in the Liberal party would be in jeopardy if they were on the 'wrong side' in a nomination battle," he said in an email to Innes.

"We have all seen what Liberals fighting with Liberals can do, not only to the electoral chances of our party but to its soul. Our leader has made it clear that this kind of behaviour is not acceptable to him, nor to the thousands of people who have embraced the new way of doing politics under Justin Trudeau's leadership."

Innes did not immediately respond to a request for comment. MacNaughton said she has denied the allegations and he acknowledged he's seen no evidence that she personally has been involved.

"We all know where this comes from and it's not inconsistent with previous behaviour," he said, alluding to Ianno, who was a key organizer of the caucus revolt against former prime minister Jean Chretien.

Trudeau has promised open nomination meetings in every riding across the country, including his own. But those would-be contestants must first win the approval of the party's "green light committee," which has the power to block those who don't meet certain standards.

For instance, prospective nominees who have yet to pay off past leadership campaign debts, such as David Bertschi and George Tkach, have been warned they'll be blocked unless they can demonstrate a credible plan to retire their debts.

The decision to veto Innes adds bad-mouthing other Liberals to the list of verboten attributes.

MacNaughton acknowledged the decision will doubtless spark criticism that Trudeau's promise to hold open nominations is hollow, that his team is showing "favouritism" to ensure victory for the leader's hand-picked star candidates.

Some of Trudeau's recruits, including Freeland, were showcased at the party's convention last month, prompting some grumbling that he's giving them a leg up in nomination contests. His team countered that opening up nominations doesn't mean the leader can't promote his preferred winners, as long as the contests are run fairly.

Nor does it mean the party has to tolerate a situation in which "the candidate who is left standing is the one who can browbeat and intimidate enough people into showing up (to vote)," MacNaughton said.

Innes wanted to run for the Liberal nomination in Trinity-Spadina, the downtown Toronto riding facing a byelection after Olivia Chow resigned Wednesday to run for mayor.

Ianno represented the riding from 1993 until he was defeated by Chow and the NDP in 2006. Innes herself twice lost to Chow in 2008 and 2011.

Due to redistribution, Trinity-Spadina and Freeland's neighbouring riding, Toronto Centre, will become three new ridings for the 2015 general election.

As a condition for being green lit, the party asked Innes to promise, should she win the byelection nomination, to seek the nomination in the new riding of Spadina-Fort York in the general election, rather than University-Rosedale, where Freeland intends to run.

Similar requests have been made of other prospective byelection nominees, aimed at keeping them focused on the byelection, not on a possible future nomination war between two incumbent MPs, MacNaughton said.

"Not only did you reject this solution out of hand but your campaign team began to use intimidation and bullying on young volunteers," he says in the email to Innes.

Party brass received several complaints from young Liberals who had worked on Freeland's byelection campaign about the conduct of Ianno.

MacNaughton said it's "a sad commentary" on the way Liberals spent two decades fighting each other, in the process reducing the once-mighty party to a third party rump.

Under Trudeau, the party has revived and his team is determined to nip any resumption of infighting in the bud.

"We've recruited thousands of new people to the party and if this is their first experience it will certainly turn them off," MacNaughton said.