The Liberal Democrats are set to appoint Nicol Stephen as Scottish leader for another four years, despite the party's lacklustre performance at the Holyrood election.

Mr Stephen has secured the support of all 15 of his parliamentary colleagues at Holyrood, which makes it technically impossible under the party rule book for there to be any challenge against him.

Under rules agreed in 2000, the leader of the Scottish Liberal Democrats must be an MSP, while the deputy must be a Westminster MP, with the posts to be agreed at Scottish party conference every four years following a Holyrood poll.

With all the other Holyrood members endorsing Mr Stephen, it means that although nominations do not close until August 14 the race is in effect over before it has even begun.

When he took over from Jim Wallace two years ago Mr Stephen inherited a party in government and looking to inflict serious damage on the Scottish National Party. Instead, the LibDems lost the crucial Gordon seat to Alex Salmond, Argyll and Bute to the Nationalists, and saw Roxburgh and Berwickshire fall to the Tories.

In the wake of that, the party decided not to do a deal with the SNP and left government after eight years at the heart of power in Scotland.

With former minister, Shetland MSP Tavish Scott, adopting a high public profile in recent weeks there had been speculation about a challenge to Mr Stephen this year.

The Aberdeen South MSP was elected leader when Jim Wallace stood down two years ago, and Mr Scott, as his most obvious rival, threw his weight behind his candidacy.

Now Mr Scott is among the MSPs whose decision to endorse a second term for Mr Stephen means he is now certain to hold office for six years.

"I am not at all surprised by the way this has worked out," said Mr Scott. "If I had wanted to stand as leader of the Scottish Liberal Democrats I would have done so two years ago.

"That policy of continuity was the strategy every time Jim Wallace stood, and I think you will find it's not in the tradition of Liberal Democrats to have a bloodletting whenever they decide to consider the leadership."

Mike Rumbles, one of Mr Stephen's fellow north-east MSPs, said: "I am absolutely certain Nicol Stephen will be re-elected in October. He is the best man for the job and he has the backing of all the MSPs, including myself."

Mr Stephen will now be leader of the Scottish Liberal Democrats for the next four years, through the next Holyrood elections campaign.

The party's only decision in the short term will be the election of a deputy leader, who must be a Westminster MP.

Michael Moore is the current deputy but with his new role as foreign affairs spokesman it is likely he will step down, with new shadow Scottish Secretary Alistair Carmichael likely to take over.