Scottish Secretary Alistair Carmichael has ruled out running to lead the Liberal Democrats at Westminster.

The cabinet minister said he did not want his party's top job - despite predictions he could be one of the few Lib Dem MPs to keep their seats in the General Election.

The demands made of modern party leaders were "enormous", and would mean he would not see enough of his family, he said.

However, the Orkney and Shetland MP said that he hopes to remain a Scotland Office minister after May.

Mr Carmichael's constituency is widely thought to be one of the safest for the Lib Dems in Scotland.

But polls suggest that the party will struggle to hold on to many of their Westminster seats on May 7.

Labour are currently running a "decapitation" strategy against Lib Dem leader Nick Clegg in Sheffield Hallam.

Even if Mr Clegg does hold on a swathe of seat losses across the UK could force his resignation.

There were reports last year that Mr Clegg had considered quitting after a dreadful result in the European Parliament elections.

Mr Clegg, who has become a lightning rod for criticism over his party's tuition fees U-turn, could potentially save his job if the Lib Dems enter another coalition government, either with the Conservatives or with Labour after May.

But it is thought a number of senior Lib Dem figures are already preparing for a possible leadership contest.

Asked if he would like to be Lib Dem leader, Mr Carmichael said: "No. There's no vacancy and I have the constituency that is furthest away from London.

"I have got a family that still includes school-age children.

"And the commitment that it takes to be party leader in modern politics is enormous."

He added: "My family already miss out on a lot just by virtue of the fact that I'm an MP and I'm a minister and I'm away from home every week.

"At least I feel that they miss out on a lot, they might feel differently."

He also said that he hoped "of course" to remain a minister after May.

"I came into politics to make a difference and from that point of view although it has been a really tough five years I don't regret a second of it," he said.

"I can point to the delivery of polices that have been aspirations of previous generations who have never had the chance to put them in action.

"So I can say that in previous elections I promised that we would restore the link between pensions and earnings or inflation - we've done that.

"We promised in the past tax changes - we have done that.

"On the home front (there are) all the various local initiatives I have been able to support, like the lower rate of fuel duty for island motorists".

He did not rule out becoming a Scotland office minister, a step down from his current cabinet position, if the Lib Dems were in another coalition after May.

"Who has a job anywhere is a job for the Prime Minister and the Deputy Prime Minister, that's well above my pay grade. I have loved every second of being a minister" he said, "but I've loved every second of being an MP."

Last January Mr Carmichael also said that he saw a future career for himself outside politics.

In an interview he discussed a "fourth" job choice - following stints as a lawyer, hotelier and politician, saying : "I'm not going to be a professional politician for the rest of my life."

As Scottish Secretary, Mr Carmichael led the UK Government's fight against independence in the run up to last September's referendum.

Born in Islay, he worked as a hotel manager and as a lawyer before being elected to Westminster in 2001. After the Tory-Lib Dem Coalition was formed in 2010 he initially served as Lib Dem chief whip, enforcing party discipline.

He replaced fellow LibDem MP Michael Moore as Scottish Secretary in October 2013.