The Scottish Greens have said they will not back Conservative calls for Michael Matheson to resign, while also saying they have concerns about a Holyrood committee which ordered a sanction against him.

The Greens said a member of the Standards Committee had apparently “pre-judged” Mr Matheson’s case, echoing concerns from the First Minister.

John Swinney said he will not support a 27-day Holyrood ban for Mr Matheson, who incurred a near-£11,000 data roaming bill on his parliamentary iPad while on a family holiday to Morocco.

The SNP’s Mr Matheson initially stated his device had been used only for parliamentary purposes, before later confessing his teenage sons had used it as a wi-fi hotspot to stream football.

READ MORE: Swinney defends decision to challenge Matheson probe sanction

While he paid back the bill in full and apologised, Holyrood’s Standards Committee also recommended a 54-day salary suspension, with Parliament expected to vote on the sanctions.

In the coming week the Conservatives will table a motion calling for Mr Matheson to resign, but this will not be legally binding.

A Scottish Greens spokesperson said: “Michael Matheson made a mistake for which he has already been punished, but it is the view of the Green group of MSPs that it is correct that he receives further parliamentary sanction, and we will vote for such action.

“However, we are united in our concern that the Standards Committee does not appear to have a consistent approach to the level of sanctions proposed, has allowed members to pre-judge the case, and has also seen draft proposals leaked.

“It is clear that if it is to retain confidence, the committee will require a more rigorous approach in future.

“What we will not do is support the unscrupulous and vindictive calls for him to resign from the Tories who are being not just shallow and callous, but abusing their positions as parliamentarians through partisan self-interest which is the hallmark of Conservative politicians the length and breadth of the country.

“Their actions shame their benches and the public will see through their nasty opportunism. The Scottish Parliament and MSPs within it should observe the highest standards and lead by example. We hope SNP and Tory members will now reflect upon this sorry chapter.”