The NDP leader said the party was too busy to create a Quebec version in time for the current election campaign, which will send Quebecers to the polls on Sept. 4.
But Mulcair indicated Friday the NDP is planning to build a provincial cousin before the next election.
The creation, he believes, would add a missing component to the province's political playing field: a left-leaning, federalist voice.
The province's two major federalist parties — the Liberals and the Coalition for Quebec's Future — are both considered right-of-centre.
"We think there's a place for us on Quebec's chessboard," Mulcair said following a speech in Montreal.
"There will be a provincial NDP, but for the next election."
The former Quebec cabinet minister said the NDP currently runs candidates in all provinces and territories. Soon, the party hopes to have hopefuls in each of Quebec's 125 ridings.
The NDP's national president, Chantal Vallerand, reserved the name "Nouveau parti democratique du Quebec" in June with the province's electoral authority. The party has not yet registered a provincial NDP.
The federal New Democrats made historic strides in Quebec in the 2011 federal election. They now hold 58 of the province's 75 seats after nearly sweeping the sovereigntist Bloc Quebecois completely off the map.
Mulcair said the party's growing presence in Quebec, which brings improved structural and financial support, encouraged the NDP to enter the provincial political ring.
The timing just wasn't right during the last year.
"It was inconceivable for us, even though we had lots of pressure from our base of supporters," Mulcair said.
"We came out of a year during which we won 103 seats, we moved from the fourth political party to official Opposition and we lost a charismatic leader who worked very hard to get us there."
Despite the NDP's intention to enter Quebec provincial politics, Mulcair swiftly refused to answer any questions about the ongoing campaign.
"I'm going to be called upon to work with whatever party forms the government," he said.
"So you won't hear me as the leader of the official Opposition in Ottawa getting involved in the provincial campaign right now."
The co-leader of the left-wing Quebec solidaire questioned Friday why Mulcair would launch into such a "hypothesis" in the middle of Quebec's election campaign.
Amir Khadir, the only person his sovereigntist party has ever had elected to the provincial legislature, told The Canadian Press that Mulcair should instead be focused on the more important tasks at hand.
Khadir said Mulcair must concentrate on carrying out the federal NDP's job "to defend Quebec from decisions made by Harper's right-wing, monarchist government that collides, at all levels, with the aspirations of Quebecois society."
He then added: "The Quebecers who voted for the NDP in a large majority did it to block the Harper government — not to bring an NDP to Quebec."
If Mulcair's plan is realized, it wouldn't be the first time the NDP has had a ballot-box presence in Quebec.
A party called NDP-Quebec ran candidates in several provincial votes, but not in a general election since 1994. The party had 41 candidates under its banner that year and earned less than one per cent of the overall vote tally.
Following that election, the party's support for Quebec independence prompted a split with the national NDP.
NDP-Quebec later morphed into the Social Democratic Party of Quebec, which was led by convicted FLQ terrorist Paul Rose. The paroled Rose had spent 12 years behind bars for the 1970 kidnapping and murder of then-Quebec labour minister Pierre Laporte.
- with a file from Lise Millette
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