THE Scottish Government’s chief whip has singled out an SNP defector as an example of an independent-minded MSP holding ministers to account.

Minister for parliamentary business Joe FitzPatrick heaped praise on John Finnie in a meeting of Holyrood’s standards committee.

Although he was elected an SNP Highlands and Islands list MSP in 2011, Mr Finnie quit the party in protest less than 18 months later over its support for Nato.

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The former police officer is now a Scottish Green MSP.

The standards committee is examining the role of parliamentary liaison officers (PLOs), aides who act as the eyes and ears of cabinet secretaries in parliament, but can also ask quiz them in the Holyrood chamber, leading to accusations of “softball” questions.

Asked by Labour’s Daniel Johnson if PLOs were too close to government to scrutinise it, Mr FitzPatrick said: “In the last parliament, the majority of MSPs were members of the SNP.

“The are some very good examples of people who were PLOs scrutinising the cabinet secretary they were appointed to serve.

“When John Finnie was a member of the SNP group, he was the parliamentary liaison officer for Kenny MacAskill.

“If anybody cares to look at the record, they will see lots of occasions John Finnie robustly questioned Kenny MacAskill on justice issues.

“The challenge for all us to some extent is to put aside the party hat.”

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As minister for parliamentary business, Mr FitzPatrick is in charge of steering the government's programme through parliament and ensuring MSPs are disciplined in their voting.

His praise for the only MSP to have made a successful move from one party to another was therefore highly unexpected.

Until last month, PLOs sat on the committees meant to scrutinise their cabinet secretaries.

But after an outcry about conflicts of interest, the First Minister rewrote the ministerial code and this no longer happens.

The committee asked whether the role of PLOs should, like that of ministers, be explicitly defined in the parliament’s standing orders.

Green MSP Patrick Harvie, the committee’s deputy convener, said that as PLOs had a foot in both government and parliament there should be “mutual agreement” about their role, not a government-only definition.

Mr FitzPatrick resisted the move, saying it would be “very strange” if parliament defined the function of people appointed by the First Minister to support government ministers.

He said: “That would be quite difficult. I have confidence in the system."

However Tory MSP John Scott said there remained “a clear conflict of interest”.

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Mr Finnie said later: "The role of every elected parliamentarian is to scrutinise and make good law. I always work on the basis that I have to explain my decisions to my constituents."