Mr Kennedy says the Lib Dems have an 'internal strength'

Under the party's constitution, the leader has to be re-elected within 12 months of each new Parliament.

"I am delighted to be returned unopposed as leader - this is a reflection of the unity of the Liberal Democrats," he said.

Following the 2005 general election, there are 62 Liberal Democrat MPs - the largest number since the 1920s.

The Liberal Democrats are very proud of our leader Lord Rennard Lib Dems chief executive

Mr Kennedy, who has been party leader for almost six years, added: "I am looking forward to working with the party's new MPs and leading the party to further successes in the future."

Party chief executive Lord Rennard said: "Charles Kennedy has already led us to two successive increases in both seats and votes.