Chief Secretary to the Treasury Danny Alexander has lost his Inverness seat to the SNP.
The Liberal Democrat - who played a key role in forming a coalition with the Tories in 2010 - lost the seat he had held since 2005 to Drew Hendry.
It is the latest blow for the Liberal Democrats on a disastrous night for the party.
A Liberal Democrat source earlier told ITV News that it is going to be a "bad night" for the party.
An exit poll predicted that the party could be left with just 10 MPs.