JIM Murphy's leadership of Scottish Labour is under pressure after the first MSP to break ranks has called for his resignation.

Mr Murphy is expected to face a no confidence motion at the party's ruling Scottish Executive Committee on Saturday.

If the motion is passed it doesn't require Mr Murphy to resign but would leave him in an even more difficult position.

Scotland's biggest public sector union also said it would not oppose a change in leadership and said voters did not see him as a "credible messenger of Labour values".

He received a boost when it was stated the "overwhelming majority" of MSPs supported him and Kezia Dugdale continuing to lead the party.

However Labour sources say the level of support expressed was a surprise with many who voted for him in the leadership contest thought to now be uneasy with an unelected leader, following his defeat to the SNP in East Renfrewshire.

Alex Rowley MSP has written to all his Holyrood colleagues and Mr Murphy calling for him to go.

Mr Rowley, who backed Neil Findlay for the leaders post last year said he was resigning from the Labour shadow cabinet team and said Mr Murphy and his team including Chief of Staff John McTernan should go.

He said: "I sincerely hold the view that you continuing as leader whilst not in the Scottish Parliament, and not in an elected position holding a democratic mandate, means you will become an unhelpful distraction from the real issues that Scottish Labour must focus on."

Mr Rowley praised Mr Murphy's dedication and hard work during the campaign but said change was now needed.

Mr Rowley was one of the First MSPs to leave the meeting in Glasgow this week but he declined to comment at the time.

In the letter he said: "I have given that a lot of thought and consideration and I concluded that it would be disloyal and damaging to Labour were I not to speak out. I believe now, more than ever, that we in Scotland need a strong relevant Labour Party and we will not achieve this under your leadership therefore I have no choice but to speak out."

Unite and Aslef unions have already called for Mr Murphy to go and are expected to vote in favour of any no confidence motion

Unison officials met to discuss the labour leadership and said it would call for resignation but would not oppose any change.

Unison Labour Link stated: "It is unprecedented for a party leader not to stand down after such a defeat, particularly when he loses his own seat. The campaign may have been energetic, but it lacked focus and clearly voters do not regard Jim Murphy as a credible messenger of Scottish Labour values.

"Scottish Labour has a limited period of time to reorganise itself to provide a credible challenge in the Scottish Parliament elections next year. There is very little time for a new leader to take the necessary actions, which require more than simply a change of leadership. Against that is the risk of further damage being done in next year's election if no change takes place.

"The current leader was elected fairly recently by a clear majority of members. However a majority of Unison Labour Link members did not share that view. Given that, we do not believe it is Unison's place to initiate a change in leadership. "However, if there is a wider movement proposing change Unison Labour Link would not oppose it."