After the Dutch general election of 1998 Timmermans was elected a Member of the House of Representatives for the Labour Party and was installed as Member of the House of Representatives on 19 May 1998.
Setelah pemilihan umum Belanda 1998 Timmermans terpilih menjadi Anggota Dewan Perwakilan untuk Partai Buruh dan dilantik menjadi Anggota Dewan Perwakilan pada 19 Mei 1998.