Michael Matheson looks set to be suspended for 27 days from parliament and lose 54 days salary after the SNP sensationally U turned on their decision to back him.

First Minister John Swinney said last Thursday he would not support the sanction recommended by the standards committee saying the committee had been prejudiced because of previous comments made by one of its members Annie Wells.

Mr Swinney told Holyrood that if a constituent was facing disciplinary action at work and their employer made similar comments, he would “come down on that employer like a tonne of bricks”.

He added: “That is the situation that Michael Matheson is facing here, and that is why I will not be supporting the sanction.”

His remarks lead to reports that because of parliamentary arithmetic the vote tomorrow would be close with SNP MSPs likely to oppose the punishment, while opposition parties would vote in favour. It was unclear how Alba MSP Ash Regan would vote with the prospect her vote could help decide his fate. She said on Wednesday morning she would support the sanctions proposed by the committee.

SNP set out their new position on Tuesday night amending the committee convener's motion which demands Mr Matheson's suspension of 27 days and loss of 54 days salary.

But the motion, lodged by deputy first minister Kate Forbes did not attempt to change the sanction proposed by the committee.

It is now unclear how SNP MSPs will vote on Wednesday afternoon. Should they abstain on the sanctions vote the motion would pass and Mr Matheson would be suspended.

Mr Swinney told the BBC his opinion had not changed causing some confusion.

“I won’t be supporting the sanctions that are put in place," he said.

"Our position will be put to parliament today and parliament will hear all about that.”

Mr Matheson's suspension would take effect from Thursday and is understood to be the longest suspension faced by an MSP following a committee's recommendation.

READ MORE: 'Swinney ill-advised to defend Matheson from MSPs sanctions'

The SNP amendment does though raise concerns over potential bias in the committee's decision making process and notes that a former member Stephen Kerr withdrew from the body after commenting on the case.

It adds that it agrees with Mr Kerr "that to have remained as a committee member 'would have been wrong' as he 'couldn’t meet the test to be unbiased' and compares Ms Wells's status to remain on the committee. The amendment also goes on to call on "the Scottish Parliamentary Corporate Body to initiate an independent review of the Parliament’s complaints process to restore integrity and confidence in the Parliament and its procedures."

Holyrood's cross party standards committee of MSPs last week recommended the sanctions against the former health secretary over a near-£11,000 data roaming charge bill on his parliamentary iPad whieh he racked up while on a Christmas family holiday in Morocco.

READ MORE: Swinney will not support Matheson Holyrood ban

Conservative, Labour, Lib Dems and Scottish Greens are expected to back the motion calling for the sanctions to be imposed on Mr Matheson, while SNP MSPs had been expected to oppose following Mr Swinney's remarks.

The debate and vote on the standards committee's report will take place in Holyrood from 2.50pm to 3.20pm tomorrow.

The motion tabled by Martin Whitfield, the Labour MSP who is convener of the standards' committee, states: "That the Parliament notes the Standards, Procedures and Public Appointments Committee's 1st Report, 2024 (Session 6), Complaint against Michael Matheson MSP (SP Paper 597), and agrees to impose the sanctions recommended in the report that the Parliament excludes Michael Matheson MSP from proceedings of the Parliament for a period of 27 sitting days and withdraws his salary for a period of 54 calendar days to take effect from the day after this motion is agreed."

A separate Conservative led debate calling for Mr Matheson to resign as a MSP will be held immediately afterwards. The SNP and the Scottish Greens will not support the Tory motion meaning that it is highly unlikely the motion calling from him to step down as an MSP will pass.

The SNP U turn came after James Mitchell, professor of public policy at Edinburgh University, said he did not think it likely the First Minister should have defended Mr Matheson from the committee's recommendations and doubted if he would have pursued such a course of action if key aide Kevin Pringle was still advising him.

Mr Pringle, a long serving SNP strategist, who advised Alex Salmond, Nicola Sturgeon and Humza Yousaf when they were first ministers, was not rehired by Mr Swinney.

Professor Mitchell said the ongoing row over Mr Matheson's actions was overshadowing the SNP's general election campaign and along with other troubles gave voters the impression of a party that was "entitled".

Speaking to journalists during a visit to the Scottish Poetry Library in Edinburgh today, Mr Swinney said the row over Mr Matheson's sanctions had not overshadowed the first week of the SNP’s General Election campaign.

“I’ve been out and about, talking to lots and lots of people as part of my travels around the country and people are talking to me about a whole range of different issues which matter to them,” he said.

“Those matters are about the effect of austerity on our public services, businesses that are telling me that Brexit is causing them ongoing difficulties and then I can’t speak to a household without them expressing concern about the cost of living.

“So, those issues are the issues that I’m engaging on with members of the public.”

A spokesperson for the SNP Holyrood Group said: "The procedures of the Parliament must be beyond reproach - not open to bias, prejudice and political motivation.  

"There is a need for a review of the complaints process to restore integrity and confidence in the Parliament and its procedures to ensure we are never again in a position where politics is put before process and prejudice is put before Parliament."