\nScottish Independence: Full Coverage\n Sir Bob Geldof has infuriated independence-minded Scots by urging them to vote to maintain Scotland's place within the United Kingdom ahead of a historic referendum. Speaking in London's Trafalgar Square, Geldof described the United Kingdom as "one of the greatest ideas ever invented for the modern age". "Before there was a United States, before there was a United Nations, before there was a united this, that and the other there was a United Kingdom and it was an extraordinary meeting of very different minds of two extremely close cousins," he told the gathered crowd. "And what a construct this thing is. Because Scotland is a feeling. England is a feeling. Wales is a feeling, Ireland a feeling. But the United Kingdom is one of the greatest ideas for the modern age." Readers on Twitter focused on the irony of an Irishman appealing for British unity. Ireland won independence from England in 1921 after an armed uprising. \n Hey #Geldof go and make your plea in Glasgow / Edinburgh / Cardiff / Belfast...or Dublin ya prick! #Punkmyarse\n— gojo-music (@gojomusic1) September 15, 2014 The Irish-born entertainer, who rose to fame as a rock star in the 1980s, made the appeal alongside celebrities Eddie Izzard, Al Murray and Jenny Colgan. Geldof was awarded an honourary knighthood by Queen Elizabeth II in 1986. Uncertainty over the outcome of the election has prompted British PM David Cameron to make last-minute pleas to the Scottish to stick with the UK. The issue of Scottish independence has polarised the public in the British Isles, drawing the comments of celebrities weighing in on both sides. Author JK Rowling wants Scotland to stay with the UK, while Sean Connery, arguably Scotland's most famous actor, supports independence. Scottish novelist Irvine Welsh supports independence, as well. "I always think the Union is nature's way of stopping the Scots ruling the world," he was quoted as saying. "We'd be unstoppable if we were independent." Singer Susan Boyle, made world-famous on Britain's Got Talent, opposes independence, saying she is a "proud, patriot Scot" who is passionate about her heritage but that she is "not a nationalist". The referendum will be held on September 18. Polling suggests a close vote with many younger Scots inclined to support independence, with issues of representation in British politics and within Europe key issues. England and Scotland have been united since 1707.