A new Conservative attack ad takes aim at Liberal Leader Justin Trudeau鈥檚 position on the mission against the Islamic State, but it uses the terrorist group鈥檚 own horrifying propaganda images.

In the online ad, posted on the Conservative Party鈥檚 , Trudeau is shown in a CBC interview saying he would end the CF-18 bombing campaign against the terrorist group, also known as ISIS or ISIL.

The ad uses Islamic State propaganda, including gruesome images of prisoners facing death by drowning and beheading -- and those images may actually violate the government鈥檚 own anti-terror law.

The new C-51 legislation gives a judge 鈥渢he power to order the seizure of terrorist propaganda or, if the propaganda is in electronic form, to order the deletion of the propaganda from a computer system.鈥�

鈥淗ere they are using the music and images of a terrorist organization. So not only does it undermine decency, but it undermines the credibility of the Conservatives on their own bill,鈥� NDP MP Paul Dewar told CTV News.

Advertising executive Tony Chapman wondered how the uses of ISIS imagery would help the Conservatives score political points.

鈥淣ot only are they providing free advertising for ISIS, they鈥檙e completely offside and driving Canadian politics to a new low,鈥� said Tony Chapman.

Meanwhile, Prime Minister Stephen Harper continued the political attack Thursday during remarks to reporters in Quebec City.

Harper suggested Trudeau would cut relations with Canada鈥檚 coalition allies in the fight against Islamic State in Syria and Iraq. He also accused Trudeau of wanting to 鈥渂ecome best friends鈥� with Iran, 鈥渙ne of the state sponsors of terrorism in the world.鈥�

He then slammed Trudeau and NDP Leader Tom Mulcair for 鈥渋rresponsible electoral politics鈥� in their positions on the anti-ISIS mission.

The federal NDP made huge strides in Quebec in the last federal election, picking up 58 of the province鈥檚 75 seats to help them reach a total of 95 seats in the House of Commons.

Mulcair has already stated that he would pull Canadian troops out of Iraq if he becomes prime minister. He said last March the NDP would be open to Canada participating in a UN or NATO mission, but not 鈥渁n American-led mission.鈥�

Harper鈥檚 comments about Trudeau come days after the Liberal leader said he would halt Canada鈥檚 bombing missions against ISIS in favour of sending military personnel over to train local troops on the ground.

On Thursday, Trudeau reiterated his position.

鈥淲e just don鈥檛 necessarily do it in the way Mr. Harper doing by dropping bombs; there鈥檚 much we can do around training and humanitarian support,鈥� he said.

Trudeau has also said he would explore re-opening relations with Iran. In 2012, Canada suspended diplomatic relations with Iran and closed its embassies in that country.

With a report from CTV鈥檚 Richard Madan