Isles MP Alistair Carmichael has been given the backing of his Holyrood counterpart and the local Liberal Democrat group.
He has been the subject of fierce criticism since it was revealed he was behind a controversial leak ahead of the General Election.
A demonstration was held at the weekend, with SNP supporters calling for Mr Carmichael to stand down from his Orkney and Shetland seat – which he won with a very slim majority of just 817.
But Shetland MSP Tavish Scott said Mr Carmichael should be forgiven for what he had done.
“I am very disappointed by Alistair’s actions. We have worked together for 14 years for Shetland. People come to see both of us to solve problems. I too feel let down. No wonder many people across the islands do too.
“But Alistair’s handling of this matter is not the Alistair I know. The Alistair I know worked with hundreds of Shetlanders to keep Sakchai Makao out of the hands of the UK Home Office and in his adopted home of Shetland.
“The Alistair I know worked with coastguard staff to save the Lerwick station. The Alistair I know was frustrated by high petrol prices at home and did something no one else had ever done – got petrol taxes cut for the islands.
“So I have spent the time since last Friday wondering why he made such a serious mistake and one that he knows will cost him the trust of many people.”
Mr Scott said the SNP will have “won” if Mr Carmichael resigned, adding few seemed to see the nationalists “abject hypocrisy”.
“Salmond blatantly lied about legal advice on Scotland’s membership of the EU, he said. “The difference between Alistair and Salmond is Alistair has confessed and apologised.
“The political motivation of the SNP and the yes campaign is obvious and increasingly personal and unpleasant. I detest mob rule and that is what this now looks like. It is not the Shetland I know.
“The second option is that he listens to his constituents, real Shetland folk who will give him a fair hearing.
“If he can demonstrate that he can get back to being a determined, effective local MP then people will accept that. Alistair has a long road to recovery with many people. But he should walk that road.”
Mr Scott’s comments came after the Shetland Liberal Democrats held a meeting last night to discuss Mr Carmichael’s involvement in the leaked memo.
A statement issued by Lerwick-based branch secretary Beatrice Wishart on behalf of the local executive expressed “surprise and disappointment” at Mr Carmichael’s actions and his “lack of judgment”.
The statement read: “However, the members agreed that Alistair has rightly taken full responsibility and has apologised to all concerned, not least to the people of Orkney and Shetland.
“The members agreed that Alistair is an excellent constituency MP. He has achieved much for Shetland in the last 14 years, particularly during his five years in government, where his experience and expertise were used to great benefit for the Northern Isles.
“He has reinforced his commitment to carry on representing this constituency, as he was elected to do, and he retains the full confidence of the executive.”