In February 2007, Scullion was elected to the position of deputy Senate leader of the federal National Party and was subsequently promoted to the positions of deputy parliamentary leader of the National Party and leader of the party in the Senate on 3 December 2007, following the coalition's defeat. On 6 December 2007 he was named as Shadow Minister for Agriculture, Forestry and Fisheries in the shadow ministry chosen by new Opposition Leader Brendan Nelson. In 2008, he was defeated by Barnaby Joyce for the Senate leadership, but retained the deputy leadership of the National Party.