Campaigners for and against Britain leaving the European Union traded accusations late Tuesday in an often heated final television debate before Thursday's referendum, ignoring widespread calls for both sides to tone down their rhetoric.
"Your campaign hasn't been project fear, it's been project hate as far as immigration is concerned," Labour's Sadiq Khan, London's first Muslim mayor, told Vote Leave co-leader Boris Johnson.
Khan said voters faced the "most important decision for a generation" on Thursday, urging voters to make "a positive, patriotic choice to remain [in the EU]."
He and Johnson led two panels of three politicians in the 90-minute BBC debate on the pros and cons of a Brexit in front of an audience of some 6,000 at London's Wembley Arena.
Khan accused Johnson, his predecessor as London mayor, of changing his position on the benefits to business of EU membership, while Johnson said Khan had changed his views on the drawbacks of immigration and is part of a Remain campaign that "keeps talking down our country."
Johnson was greeted with loud cheers and some jeers as he closed the debate, telling voters they have a "clear choice" between the Remain side who "speak of nothing but fear and we, on our side, who speak of hope."
"If we vote to leave and take control, I believe that this Thursday could be our country's independence day," Johnson said at the end of a debate that focussed on the economy, EU migration and British sovereignty.
Opposition leader Jeremy Corbyn had earlier appealed for "a sense of proportion and a sense of decency" in the debate over immigration, which has dominated the final weeks of campaigning.
Speaking at a Remain campaign event, the Labour chief said some popular British media had failed to have any serious discussion about the issues surrounding immigration.
He urged voters to "think the thing through in a balanced way," saying EU migrants were "living, working, paying taxes in Britain, and helping us run our health service and many, many other services."
People concerned about the impact of immigration should not blame individuals "because of their nationality or because of the colour of their skin or their ethnicity," Corbyn said.
"It is governments that underfund and under-provide services, and companies that grossly exploit and seek to divide people [who are to blame]," he said, saying he would press Cameron's government to provide extra funds for areas with high numbers of migrants.
The latest polls put Remain marginally ahead of Leave, but an online survey by Crowdpac suggested that about one-third of voters had not reached a final decision on how to vote.
Vote Leave co-chair Gisela Stuart, a Labour member of parliament who joined Johnson on the BBC panel, said immigration had suppressed wages and "hits the poorest hardest."
Prime Minister David Cameron called a press conference outside his official residence in London earlier Tuesday to appeal to older voters to "remember the hopes and dreams of your children and grandchildren" and remember they "can't undo the decision" on a British EU exit, or Brexit.
"The next generation will have to live with the consequences far longer than the rest of us," Cameron said.