Scottish Labour leader Wendy Alexander has been given "unanimous" support by her party's MSPs to stay on in the job.
She refused to resign over the £950 illegal donation accepted by her leadership campaign team from Jersey-based businessman Paul Green.
Ms Alexander acknowledged that mistakes had been made, but said she would fight on to clear her name.
She said she had correspondence which showed her determination to ensure that campaign donations were above board.
Duncan McNeil, chairman of the Scottish Parliament Labour group, said Ms Alexander was given "absolutely unanimous" backing by party MSPs during one of their regular meetings.
Meanwhile Charlie Gordon, who asked Mr Green for the donation, said he would make a decision on his "political future" later in the week, but declined to be drawn on whether he would resign as the MSP for Glasgow Cathcart.
Mr Gordon, who has already quit as Scottish Labour transport spokesman, had told the campaign team that the donation was "under the auspices" of a Glasgow firm in which Mr Green had a controlling interest.
He later said he had been wrong.
The donation was illegal because it came from someone not on the electoral register and, in his first interview on the controversy, Mr Green said it was clearly a personal cheque.
Later at Westminster, Scottish Labour MPs have expressed anger at the difficulties the party is facing over illegal donations.
About 30 MPS met on Tuesday and many were incredulous that illegal and secret donations had been accepted both north and south of the border.
But they also expressed support for Wendy Alexander as long as she was cleared of wrongdoing by the Electoral Commission.
Speaking at the Scottish Parliament earlier in the day, Ms Alexander attempted to put the crisis behind her by expressing determination to get on with the job of holding the SNP government to account.
She said: "I have never sought to mislead. I am not dishonest in any way and I have always believed that politicians should have the highest standards of integrity.
"My campaign did not set out to intentionally mislead or break the rules. Mistakes have been made.
"It would be easy to quit, but also wrong. To give up this job in these circumstances would be also to give up my reputation for integrity and honesty and I am not prepared to do that."
Ms Alexander said she would be informing the Electoral Commission watchdog "in full", adding: "For the record, there is repeated correspondence initiated by me personally dealing with the issue of permissibility and demonstrating my interest in ensuring that donations received were indeed permissible."
She also denied she was staying on as leader at the urging of Prime Minister Gordon Brown.
Mr McNeil said he was confident Ms Alexander would be exonerated after the Electoral Commission had examined the situation.
"I am delighted to say, as I fully expected, she has got clear, overwhelming support in the group for her to continue in the job throughout this difficult period," he said, following the meeting on Tuesday.