London: Newly-elected London Mayor Sadiq Khan has accused his predecessor of unleashing "project hate" in a desperate bid to win over voters by stirring up fears about immigration. Sadiq Khan made the remarks on Tuesday night as the Labour and Conservative Party campaigns clashed for the final time in the European Union (EU) referendum battle, The Guardian reported. The mayor and Scottish Conservative Party MP Ruth Davidson teamed up to launch the cross-party attack on former London Mayor Boris Johnson in front of an audience of 6,000 gathered for the BBC's biggest referendum event. Johnson hit back by saying Khan had recently claimed that Labour needed to listen to people’s concerns on immigration and not simply dismiss them as prejudice. He also accused his opponents of wasting time in trying to stoke people’s worries about life outside the EU. Davidson said it was not good enough that when “asked if people were going to lose jobs, Johnson said "they might or they might not”. She joined Khan in piling on to her opponent on immigration, saying Brexit (common term used for Britain's exit from the EU) was not a silver bullet and that even Johnson had called for an “amnesty for illegal immigrants, never mind the legal ones”. The night was marked by other emotional pleas as both sides strove to win support with the polls suggesting the race is still too close to call. Johnson said Thursday could be “our country’s independence day”, and that the battle was between one side that was “speaking nothing but fear and those of us with hope”. Khan raised his voice to claim: “We stay and fight, we don’t quit. Why are you a quitter?” Britain joined the EU in January 1973. In 1975, a referendum was held on Britain's membership of the European Economic Community (EEC), which was later named as the EU. The result of the referendum was in favour of Britain continuing to be a member of the EEC approved by 67 per cent of the total voters. 'Britain Stronger in Europe', chaired by businessman Stuart Rose is the main group campaigning for Britain to remain in the EU, and 'Vote Leave', chaired by Labour MP Gisela Stuart, is the main group campaigning for the country to leave.