HOLYROOD'S opposition parties have united to demand the resignation of a shamed MSP who is refusing to quit, despite being expelled by the SNP over allegations of serial domestic abuse.

Bill Walker insisted yesterday he would stay on as the "elected MSP for Dunfermline, sitting in the Scottish Parliament as an Independent Nationalist" despite a growing clamour by Labour, Conservative and LibDem politicians for him to stand down.

Labour and the LibDems said he should go immediately and the Tories called on him "to do the honourable thing".

It follows revelations in the Sunday Herald that Mr Walker, 70, has been accused of domestic abuse over four decades by three former wives and a teenage step-daughter.

A Tory spokesman said: "The SNP has taken the correct decision in pursuing this course of action and the MSP must now examine his conscience on whether he thinks it's right to continue taking thousands of pounds of taxpayers' money for the next four years. The honourable thing would be for him to step down from his role as a member of the Scottish Parliament."

LibDem leader Willie Rennie said: "He hasn't been convicted but he needs to reflect on how honest he has been with his party and recent events and think about whether he should continue."

Thomas Docherty, the Labour MP for Dunfermline and West Fife, said Mr Walker's conduct did not befit someone in elected office. He added: "I welcome the fact the SNP leadership have belatedly taken some action but Bill Walker should resign immediately.

Mr Walker's decision to remain in the Parliament means he will be able to sit as an independent MSP until 2016 on an annual salary of £57,500.

A spokeswoman for Mr Walker said yesterday he was not giving interviews, but he issued a statement confirming he had been expelled following a hearing with the SNP's Disciplinary Committee.

He was suspended by the party last month after it emerged two of his former spouses got undefended divorces after alleging he assaulted them.

Another former wife claimed Mr Walker punched and kicked her in a US hotel room, an attack it was claimed had been repeated on a holiday.

The details emerged in court documents in the National Archives of Scotland and affidavits from two of his previous wives.

Mr Walker's statement said: "The committee upheld the complaint from the party's national secretary that I had withheld from the party information about unproven allegations concerning my former marriages when applying to become an approved parliamentary candidate for the 2011 Scottish elections.

"I deny that such was the case and still maintain I completed the relevant application form in a full and proper manner.

"At no time during the vetting, selection and confirmation processes was I ever asked about my declared previous divorce proceedings and related matters."

Mr Walker said the committee decided he had breached the SNP's code of conduct by "not fully detailing all the unproven allegations against me from decades ago and so expelled me in accordance with the rules which it is entitled to do".

He insisted the expulsion had nothing to do with the allegations themselves but concerned his "claimed non-disclosure of these untested accusations in detail". He said he was currently considering whether to appeal.

Mr Walker added: "In this recent difficult time I have been greatly heartened by the number of local people who have contacted me with their support which I greatly appreciate.

"I can assure all my constituents I shall be continuing as the elected MSP for Dunfermline, sitting in the Scottish Parliament as an Independent Nationalist. There is much to do, work I look forward to pursuing over the next four years."

An SNP spokesman said they would make a full statement only after an appeal was lodged and properly discharged.