The Bloc Québécois is facing criticism for a new campaign ad that aims to win back support from the NDP in Quebec.

The ad, released online today, shows oil leaking from a pipeline then morphing into a niqab — and slams the New Democrats for their position on both issues.

The message drew swift criticism online, with NDP spokesperson Karl Bélanger tweeting the "National Front" has entered the campaign — a reference to the far-right party in France.

Le Front National vient de faire son entrée dans la campagne. —@KarlBelanger

In the ad, the Bloc Québécois warns a new pipeline is coming "even if we don't want it" if Thomas Mulcair's NDP wins the election.

It also says Mulcair has no problem with a niqab being worn during a citizenship ceremony, a reference to a Federal Court of Appeal decision this week that ruled a woman could wear a niqab while swearing the oath.

In an interview, Bloc spokesperson Dominique Vallières said the ad was only meant to point out his party's positions on the two issues.

When it comes to the niqab, Vallières said the Bloc would go farther than the Conservatives, who announced Friday it will seek a stay of the court decision in Ishaq's case.

"They want it just for citizenship," Vallières said of the Conservatives.

"We say the niqab should not be allowed for the citizenship ceremony and to vote."

He also said nothing sinister should be read into the decision to transition directly from a blob of oil to a niqab.

"There's nothing to link between the two," he said. "I think the people that did the ad connected the two because both are dark in colour."

Vallieres added that polls suggest many Quebecers agree with the Bloc's policy on the niqab.

Online, however, people were quick to slam the ad as xenophobic and racist.

Disappointed <a href="https://twitter.com/GillesDuceppe">@GillesDuceppe</a> would condone this trash. <a href="https://twitter.com/hashtag/cdnpoli?src=hash">#cdnpoli</a> <a href="https://twitter.com/hashtag/elxn42?src=hash">#elxn42</a> <a href="https://twitter.com/BlocQuebecois">@BlocQuebecois</a> <a href="https://twitter.com/hashtag/racist?src=hash">#racist</a> Thought he wz better <a href="https://t.co/SlHh7WosyH">https://t.co/SlHh7WosyH</a> —@Sue_Lib

As Gilles Duceppe trails by more than 30 points in his own riding, the Bloc Quebecois goes full racist. <a href="https://twitter.com/hashtag/elxn42?src=hash">#elxn42</a> —@LukewSavage

Zunera Ishaq talks to reporters outside the Federal Court of Appeal after her case was heard on whether she can wear a niqab while taking her citizenship oath, in Ottawa on Tuesday. (Patrick Doyle/Canadian Press)

Mulcair has previously criticized the Harper government's decision to appeal the ruling.

"I see that Muslims are often scapegoats for political debate. And that, I find it heartbreaking," he said in June.

Not everyone in the party agrees with his position, however.

Jean-François Delisle, an NDP candidate in the Mégantic—L'Érable, told The Canadian Press on Friday he believes the niqab should not be allowed while taking the citizenship oath.

He said if Mulcair opens the constitution to abolish the Senate, he could also take the opportunity to redefine the limits of religious freedom.