Scottish Labour leader Wendy Alexander is expected to announce she will stand down, the BBC understands.
Scottish Labour leader Wendy Alexander has announced she will stand down.
Ms Alexander has come under pressure after breaking donation rules and faces a one-day ban from parliament.
The Scottish Parliament's standards committee ruled that she failed to declare donations to her leadership campaign on her register of interests.
Ms Alexander, who became leader last September, is preparing to make a statement at the party's Scottish HQ.
The Scottish Parliament standards committee voted on Thursday to recommend the one-day ban on Ms Alexander.
Parliament is now in summer recess and will have to wait until September to vote on the recommendation.
Ms Alexander, the MSP for Paisley North, said clerks to the standards committee wrongly told her it was unnecessary to declare donations.
It was an extremely damaging and lasting punishment for the standards committee to settle upon Glenn CampbellBBC political correspondent
BBC Scotland political correspondent Glenn Campbell said he thought Ms Alexander had "had enough".
He said the possible one-day suspension from parliament would "hang over her for the whole summer".
"It makes it very difficult for her to operate as a political leader in the meantime," he said.
"People are very rarely suspended from parliament, nobody has previously been suspended from the Scottish Parliament for this offence and no political leader has been suspended from the parliament in which they sit.
"So it might have seemed at one level like a slap on the wrists but at another it was an extremely damaging and lasting punishment for the standards committee to settle upon."
The standards committee ruling was the latest development in the saga of donations to Ms Alexander's leadership campaign.
Last year, she expressed "deep regret" that her team accepted an illegal £950 donation from Jersey-based businessman Paul Green, although the Electoral Commission found there was not sufficient evidence to prove an offence and did not report her to prosecutors.
Meanwhile, the Labour MP for East Glasgow, David Marshall, is to resign his Westminster seat for health reasons.
A party spokesman said: "David Marshall has indicated to local members in Glasgow that he will step down as a Member of Parliament.
"We understand that he has written to party members to say that his health has deteriorated and so our thoughts and prayers are with him at this time and we wish him a speedy recovery."
