 Before the election of the first federal leader of the party (the Liberal Democrats having a federal structure in their internal party organisation), the leaders of the two parties which merged to form the Liberal Democrats, the Liberal Party and the Social Democratic Party (SDP), served as joint interim leaders.In the event that the leader dies, resigns or loses their seat in Parliament, the deputy leader (if there is one) serves as interim leader until a leadership election takes place.This has occurred three times, with Menzies Campbell serving as interim leader following the resignation of Charles Kennedy (Campbell was elected leader in the ensuing election) and Vince Cable serving as interim leader following Campbell's resignation.