Scottish Labour must "get to the bottom" of comments made by leadership hopeful Ken Macintosh regarding bullying and intimidation of members, former first minister Henry McLeish has said.

Mr Macintosh said on Saturday that the party machine has turned on his supporters to prevent a leadership contest.

The MSP and the party's deputy leader Kezia Dugdale have confirmed that they are standing for leadership after Jim Murphy announced he would resign next month.

Mr McLeish told BBC Radio's Good Morning Scotland programme: "I think people have lost trust in us and we need to work hard to fight it back.

"But I think what struck me was, and I don't know whether the allegations that Ken Macintosh is saying are true or false, when you use words like bullied and intimidated and pressurised these are serious concerns."

He added: "I think Ken has to spell out in a bit more detail.

"My main concern is for the Labour Party, this is not the way we should be conducting business, but to be fair to Ken Macintosh, if there are serious issues that have to be dealt with, then clearly the party in Scotland, the party machine as he calls it, has to have a look at what's going on."

Mr McLeish went on: "If this is a party of fraternity and fairness and and good will and transparency, let's actually practice that, get to the bottom of Ken Macintosh's comments, get Jim Murphy's report and then we can move forward."

Mr Macintosh, who also stood for leadership in 2011, told BBC Radio Scotland on Saturday: ''I want to have a contest but I've found the whole weight of the party machine yet again turning against me, trying to close down a contest.

''All the people that have been trying to support me ... the party machine has turned on them, and they are being put under incredible pressure to withdraw their support. They are being bullied, they are being intimidated, they are being pressurised not to support me so we don't have a contest.''

The MSP for Eastwood and Labour's social justice spokesman at Holyrood said the three-college system used by the party to elect leaders was ''ridiculous''.

''We need to move to one member, one vote,'' he added.

Mr Macintosh later told BBC Scotland that his comments were not against party staff but ''against the machine politics which have too much influence in the Labour Party''.

Meanwhile, Ms Dugdale, who was elected to Holyrood four years ago, said she was ''proud'' to have won the support of 20 of Scottish Labour's 38 MSPs in the first 24 hours after announcing her intention to stand.