AN SNP-LED council has called on Police Scotland to launch an investigation into how the ferry fiasco contract was awarded to tycoon Jim McColl's Ferguson Marine.

North Ayrshire Council, which has a minority SNP administration, has agreed to take the unusual step in the wake of the continuing concerns over the legality of the award of the £96m contract to Ferguson Marine in October, 2015 to provide two lifeline vessels for the Calmac fleet.

State-controlled ferry owners Caledonian Maritime Assets Limited (CMAL) has said that it was "effectively instructed" by SNP-controlled Scottish Government to award the contract for the ferries. There have been allegations that an announcement surrounding the awarding of the contract was rushed so it could be made at an SNP conference.

At the centre of Scotland's ferry-building scandal is two vessels that remain at the Inverclyde Ferguson yard, the completing of which will be delayed until at least next year – over five years later than planned - while costs have risen to £340m.

It comes in the wake of the latest allegations in a BBC documentary that Ferguson Marine had obtained a 424-page document from a design consultant setting out state-controlled ferry operator CalMac's technical requirements, while other bidders had to rely on a more limited 125-page specification. CMAL say this was not provided by them and that it seemed to be accepted that this was provided by an independent consultancy.

There were further claims that the shipyard under tycoon Jim McColl was allowed to change the design during the tendering process, making its pitch almost £10m cheaper. On the alleged change of bid, CMAL says that two bidders sought clarification which is a "normal step".

It was further alleged that there was a confidential meeting between the yard and CMAL – a courtesy not extended to other bidders in the process. But CMAL says that one face to face meeting was held with Ferguson. Other bidders participated in "similar" technical clarification engagement digitally given their non-UK locations.

HeraldScotland: First Minister Nicola Sturgeon with Jim McColl at a launch ceremony for the liquefied natural gas passenger ferry MV Glen Sannox, the UK's first LNG ferry, at Ferguson Marine Engineering in Port Glasgow. PRESS ASSOCIATION Photo. Picture date: Tuesday

The BBC documentary reiterated past revelations that CMAL may have broken its own rules by allowing Ferguson to go ahead with its bid despite being unable to provide evidence of a builders refund guarantee (BRG), a mandatory financial safeguard for when things go wrong, and they did.

Mr McColl has confirmed he only bid after receiving written guidance from transport minister Derek Mackay that refund guarantees were not mandatory to win building work.

Evidence showed that the tycoon's shipyard firm which was favoured by the SNP government could not give a commitment to provide a mandatory builder's refund as required and was unable to provide other crucial financial details including records of past achievements.

The Herald revealed in April, that taxpayers lost over £80m after ministers provided a £106m special incentive to ensure that a ferry fiasco contract could go through without the normal financial safeguards.

It was given to reassure CMAL who had "severe misgivings" over the yard's inability to provide financial guarantees were not out of pocket if anything went wrong.

The special deal came after CMAL registered concern that they were being put at commercial risk if Ferguson Marine became insolvent or failed to deliver on the ships without the full refund guarantees.

Scotland's public spending regulator Audit Scotland has told CMAL and Transport Scotland there is a duty to investigate fraud allegations and to take appropriate legal and/or disciplinary action where justified.

Now following a motion proposed by Ardrossan Labour councillor Amanda Kerr, the council is to instruct its chief executive to write to Chief Constable Iain Livingstone of Police Scotland requesting that the force carries out a "full and thorough investigation into all aspects of the ferries procurement process".

HeraldScotland: One of two Caledonian Macbrayne ferries being built in the Ferguson Marine shipyard in Port Glasgow, Inverclyde. While building two ferries on contract for CalMac, Scotland's public-owned ferry company, Ferguson Marine Engineering Ltd was put into

Labour councillor Robert Foster, who presented the motion on behalf of Mr Kerr said councillors had been "inundated" with "concerns and questions" regarding the ferries.

He said he believed the SNP group would go against an amendment which said the council should not intervene in police matters. Mr Foster said the move would help "ensure those responsible for the ferry scandal are held to account if any illegality has taken place."

"It would be reasonable to request a full and thorough investigation to be carried out by Police Scotland."

Deputy leader of the council, SNP councillor Shaun Macaulay backed a move to keep the council out of the affair while the Scottish Parliament and the public spending regulator Audit Scotland were still reviewing the matter.

He said: "I don't intend to diminish the seriousness of the matters raised... I do share the disappointment and the frustration of delay of the ferries being operational.

"I also share the general theme of the concerns raised in this motion. I intended not to be too be party political in terms of bouncing one party off another.

"Given this is a live situation right now and given the action taken by the Scottish Government, that Audit Scotland are investigating it, and that the committee and the Scottish Parliament are also investigating this, I don't see the benefit of a politician intervening at this stage on legal matters surrounding that.

"So I would suggest that we share the general themes of the motion but don't prejudge the outcome of the investigations that are currently live."

North Ayrshire Council has 12 SNP councillors, 10 Conservatives, six Labour, three Labour & Co-operative and two independents.

The motion was carried by 19 votes to 11.

Police Scotland said it is "not investigating any criminality at this time".