SCOTLAND’S ethics watchdog has been asked to investigate a Conservative MSP who resigned from his party’s front bench in a £50,000 lobbying row.

North East MSP Peter Chapman is the subject of a complaint to the Commissioner for Ethical Standards in Public Life.

The Commissioner examines potential breaches of the MSP Code of Conduct, and reports to Holyrood’s Standards Committee, which can reprimand or recommend suspensions.

It is understood one of Mr Chapman’s constituents raised the complaint after the MSP quit as the Tories’ rural affairs spokesman after what he called a “foolish” mistake.

The 68-year-old farmer admitted lobbying Aberdeenshire councillors to support a planning application from an organisation in which he had a £50,000 stake.

Mr Chapman failed to disclose his shareholding in the Aberdeen and Northern Marts (ANM) farming co-operative, which is expanding its operation at Thainstone, Inverurie.

“This is a very important part of the strategy for the group going forward and I’m just hoping that this application gets looked on in a positive manner,” he said in a voicemail left for an SNP councillor, and which was leaked to the Daily Record.

Within hours, Scottish Tory leader Ruth Davidson accepted his resignation “with regret”.

An SNP spokesperson said: “Peter Chapman has been caught out – and he was right to quit before he was sacked in disgrace.

“But this remains a serious issue for the Tories which they cannot just ignore.

“It’s important the Commissioner is given the opportunity to fully investigate Mr Chapman’s behaviour and that action is taken if he found to have breached strict parliamentary rules.”

A Scottish Conservative spokesperson said: “As Mr Chapman said, he stands to make nothing if the planning application to extend ANM Group's Thainstone centre goes through.

“He was acting not out of financial interests, but because he believes the application will be of benefit to his constituents and to the wider Aberdeenshire economy.

"Mr Chapman made an honest mistake in failing to set out his financial stake in ANM when he spoke to councillors about the matter last week, and he resigned honourably as a result."