Some raised concerns over the comments made about then candidate for mayor, Sadiq Khan during the 2016 London mayoral election which attempted to link Khan to Islamist extremists.[19] Public opinion polling at the time showed that 31% of Londoners were "uncomfortable" with the prospect of a Muslim mayor.[20] The Vote Leave campaign during leading up to the Brexit vote was also criticized as frequently portraying Muslim immigrants as a threat to future of the country.[21] The government issued Casey Review into Integration and Opportunity which aimed to examine the conditions for immigrants to the United Kingdom was criticized for its over focus of the Muslim community, as well as deeper methodical failings.[22][23] In 2014, over a third of Muslims in the UK said politicians often make bigoted comments towards Muslims.[24]