Tess Daly and Claudia Winkleman invite viewers to join them for the semi-final of Strictly Come Dancing. Fifteen couples have been whittled down to just four, with each couple having to perform two dances for a chance to win a place in the Strictly grand final. Voting lines will open at the end of the show. Once the judges' scores have been added to viewer votes, the two lowest-scoring couples will perform again in the dreaded dance-off in the results show.