She lost her seat in the 2003 elections, and left Labor to join Meretz with Yossi Beilin. Dayan headed the Meretz list in the Tel Aviv municipal elections in 2004, with the party winning 5 out of 31 Seats on council and joining Ron Huldai's coalition. Until 2008 she served as Deputy Mayor and until 2013 she was responsible for social services. Mayor Huldai chose not to include Dayan on his list of candidates for the 2013 election, effectively ending her political career.