In the January 2003 election, Bos entered a head to head race with incumbent Prime Minister and leader of the Christian Democratic CDA, Jan Peter Balkenende. Under Bos the vote and seats of the PvdA nearly doubled from 15% (23 seats) in 2002 to 27% (42 seats) in 2003. This resurgence was partially credited to Bos' charisma and youthful appearance (and according to some journalists Bos' "sexy touch"). Balkenende's CDA however remained largest the party by a margin of two seats. The ensuing coalition formation talks between Balkenende and Bos failed after several months. The CDA went on to form a government with the conservative liberal VVD, and the progressive liberal D66.