SCOTTISH Labour was last night preparing for its fifth leadership contest in eight years after it emerged that one of Jim Murphy’s closest allies looked set to stand for the top post.

Ken Macintosh was said to be considering putting his name forward for election in any contest to succeed Murphy and has been canvassing support at Holyrood.

The Eastwood MSP is likely to launch his campaign to lead Scottish Labour next month, around the time Murphy – who he once shared an office with – formally steps down.

Macintosh was understood to be phoning Labour politicians yesterday to gauge support just 48 hours after Murphy announced he would quit as leader after narrowly surviving a vote of no confidence at the party’s ruling body on Saturday.

Scottish Labour has had five leaders since its Holyrood election defeat in 2007 – Jack McConnell, Wendy Alexander, Iain Gray, Johann Lamont and Jim Murphy – and whoever takes the role faces a massive risk, with defeat likely at the Holyrood election next year amid the continuing surge in support for the SNP.

The new leader will be the sixth in eight years and faces a huge task in turning around the party’s fortunes in time for polling day next May. Scotland’s only Labour MP, Ian Murray, has already given his backing to the party’s deputy leader, Kezia Dugdale, over the weekend, describing her as an “inspiring figure” who had done a “fantastic job” at holding the SNP government to account at First Ministers’ Questions.

Labour MSP Elaine Murray last night told The National she had also given her backing to Dugdale, who she thought had performed remarkably well as deputy and had the ability to bring people together.

She said: “I think Kez has been doing a great job. She performs well at FMQs, she comes over well on television, she’s not aggressive, and she has progressed remarkably well over the last five months as deputy. I was particularly impressed at the way she took up the campaign on women offenders.

“I would like to see her take over, but I can see it’s full of dangers for her. If we don’t do well next year she might be in the position where she has to resign and I think that would be devastating for someone of her ability and who has so much to offer. She would have to think very carefully about it.”

Murray added that, judging from previous elections, it would be difficult for Dugdale to carry on as leader if the result was poor next year.

“Labour leaders all seem to fall on their swords after election defeats,” she said.

Macintosh is Labour’s shadow cabinet secretary for social justice and represents a Holyrood seat that covers a similar area to the East Renfrewshire seat Murphy lost to the SNP’s Kirsten Oswald at the General Election.

Macintosh was defeated for the post of Scottish Labour leader in 2011 by Johann Lamont. Last night he said he was “not putting out a formal statement” and refused to say what his plans were.

Neil Findlay, who stood against Murphy for the leadership last year, has made it “crystal clear” that he would not be a candidate.

The Campaign for Socialism – a left-wing group within the Labour movement from which Findlay has previously drawn support – wants Dugdale to take charge, a view also shared by Pat Rafferty, Scottish secretary of Britain’s largest trade union, Unite, which many believe played a key role in Murphy’s downfall.

The MSP who ran Findlay’s leadership campaign, Alex Rowley, is also backing Dugdale.

One source said Macintosh was unlikely to stand if Dugdale decided to put her name forward, as she had backed Macintosh when he stood against Lamont in the 2011 contest.

Dugdale is unlikely to face a challenge from finance spokeswoman Jackie Baillie or rural affairs spokeswoman Sarah Boyack who have, it is understood, both ruled themselves out. It is also believed to be “very unlikely” that health spokeswoman Jenny Marra will be a candidate.

Dugdale has yet to make any comment on a leadership challenge.