PRESSURE is mounting on ex-finance secretary Derek Mackay to stand down as Kilmacolm's MSP after being accused of 'predatory' behaviour by bombarding a 16-year-old boy with hundreds of inappropriate messages.

Mr Mackay, who represents the village as part of his Renfrewshire North and West constituency, yesterday quit the Scottish Government just hours before he was due to deliver the budget.

He stood down after it was revealed that he called a teenager 'cute' in a string of 270 texts and private social media comments sent over a sustained six-month period.

The SNP man described his behaviour as 'foolish'.

First Minister Nicola Sturgeon accepted Mr Mackay's resignation before telling Holyrood that Mr Mackay - who previously chaired the SNP as business convener - is now suspended by the party and its parliamentary group 'pending further investigation'.

Scottish Conservative leader, Jackson Carlaw, suggested the former minister should also step down as an MSP.

Mr Carlaw said: "The whole parliament will be in shock.

"I think we are all bewildered that Derek could have undertaken such a colossal lapse of judgement.

"I don't think the First Minister believes that simply accepting his resignation from government is an end to the matter.

"I think there will be huge question to be asked, parents who will be concerned, and I think many colleagues in parliament who will wonder if Mr Mackay can continue to enjoy the confidence of his constituents or parliament?"

Labour leader Richard Leonard branded Mr Mackay's behaviour 'predatory' and an 'abuse of power'.

He said: "Derek Mackay has acted beyond 'foolishly', his actions are predatory and must be thoroughly investigated.

"He has abused his position of power with a vulnerable adolescent.

"The thoughts of everyone at Scottish Labour are with the schoolboy involved and his family.

"The nature and the gravity of these allegations demands decisive action."

Inverclyde's depute provost and Kilmacolm councillor, David Wilson, was beaten by Mr Mackay at the 2016 Scottish Parliament election and says his future is a matter for him and his party.

Cllr Wilson said: "It's a matter for his party. "It's most appropriate that he stood down as finance secretary.

"The questions now being asked are entirely for him and the party."