Britney Spears hits will be sung by the five remaining X Factor acts in honour of her guest appearance on the hit ITV1 show. Spears is due to perform Womanizer, giving her first live UK performance for years. Meanwhile, teen hit sensation Miley Cyrus will perform her single 7 Things. It has also emerged that Prime Minister Gordon Brown has taken time out of his busy schedule to write to the remaining finalists. Spanish finalist Ruth Lorenzo has revealed Mr Brown wrote to her praising her for ignoring Simon Cowell's advice to sing in her native language. Lorenzo said: "In the letter that the Prime Minister sent us he said 'Keep singing in English girl. You're doing a great job! Going against Simon'. It was great." She added: "I'm glad I didn't listen to Simon. I think following my heart has gotten me here. Simon is going to have to fight hard against me. I'm a hard lady. Not even my mum could control me. I'm a rebel." The 25-year-old singer is delighted to be in the final five of the British TV talent show, thanks to viewers' support. She said: "I never thought British people were so amazing. I come from a different country, I speak a different language, I have a big accent and they still are keeping me in. It's amazing." She added: "It's great that I've gone from being seen as the Spanish girl and everyone has seen me now. And now I'm the rock chick, the Purple Rain chick." Lorenzo has had to sing for her survival on more than one occasion, but was saved by the judges the week Laura White was voted off the show. As a result, thousands of viewers complained to television watchdog Ofcom and the campaign to get her back into the competition was even mentioned in the Houses of Parliament. Lorenzo said only: "You say Laura and my heart breaks, I tell you."