In November 2008, Mactaggart attracted criticism for using unreliable statistics during as parliamentary that were not fully supported by evidence when discussing the issue of prostitution. Mactaggart was asked how those criminalised by a new law were supposed to know if a prostitute had been trafficked or not. She replied "I think they can guess", "something like 80% of women in prostitution are controlled by their drug dealer, their pimp, or their trafficker." When questioned on her claim she stated that it "came from an official Government publication into prostitution and the sex trade". However, a BBC magazine article states that "it is impossible to find that number in any research done on this subject." The Home Office have also stated that they "do not endorse or use the figure that 80 per cent of prostitutes are controlled by others". The controversy continued in January 2009 with MacTaggart told the House of Commons that she regarded all women prostitutes as the victims of trafficking, because their route into the sector "almost always involves coercion, enforced addiction to drugs and violence from their pimps or traffickers." Again this claim is not supported by any known research.