Holyrood's Standards Committee agreed by a one-vote majority that she should be excluded on the first Wednesday of the next session in September.

But Labour MSP David Whitton - speaking on behalf of the embattled leader - said the ruling was "politically motivated". Asked if Ms Alexander's position was now untenable, he said: "That is complete nonsense."

He went on: "The SNP have had people out since this complaint was raised. Certain members have appeared on every television programme and radio programme you'd care to mention. They've wanted her hung, drawn and quartered."

Parliament went into recess before the committee made the ruling, so the decision will not be ratified until it reconvenes on September 2.

The committee had already decided Ms Alexander broke the law for not registering donations above the £520 threshold as "gifts" within the required timescale.

Ms Alexander - who has a throat infection and has lost her voice - maintained she acted in good faith and had been told by clerks to the Standards Committee that she did not need to declare the donations.

The Scottish Parliament probe began after a complaint was put to the Standards Commissioner, Dr Jim Dyer, who took separate legal advice.

The seven MSPs on the committee - two Labour, three SNP, and one each from the Tories and the Liberal Democrats - considered the findings in a three-hour session. The SNP and Lib Dem MSPs voted for a one-day exclusion while the others abstained.

Mr Whitton said: "We believe this is a politically motivated complaint by a member of staff of an SNP MSP - no member of the public has ever complained. We believe that, on the face of it, it is a politically motivated decision by the committee."