SCOTLAND’S public spending watchdog has been urged to probe Renfrewshire council’s £160m too small school scandal.

Neil Bibby, the Labour MSP for West Scotland said the Accounts Commission needed to investigate the “catastrophic blunder” saying it was of “national concern.”

He said the costly gaffe could cost each of the 81,000 households in the authority around £2,000, "approximately £421 each for every man, woman and child in Renfrewshire."

READ MORE: Dargavel school blunder could cost taxpayers in Renfrewshire £160m

Due to an “error” by the council, the initial roll for the school was predicted to be around 430.

However, it should have been able to accommodate 1,100 pupils.

With more houses being built around the school, the authority announced in February that they now expect 1,500 children to need to use the school by 2033.

As a result, they now need a new building with capacity for around 800 pupils. 

Dargavel Primary is part of the privately funded Dargavel Village project, a multimillion-pound development to build 4,000 new homes on the site of a former Royal Ordnance Factory by 2034.

As part of the agreement with the council, BAE systems paid for the new school.

But because they have built it to the specifications supplied to them by the council their obligations under what is known as the Section 75 agreement, are now discharged, leaving the authority to pick up the cost for the new primary at least.

The cost of the new building will be somewhere between £42m and £45m while extending the local secondary, Park Mains High School, to accommodate another 400 pupils will be between £27m and £30m. 

That means the upfront cost will be somewhere between £69m and £75. 

To fix the problem, councillors have agreed “prudential borrowing” to be paid back at £4m a year, with officials telling elected members that the repayments could last 40 years. 

That could mean costs reaching a staggering £160m. 

And with questions over the suitability of the secondary school to accommodate such a large number of pupils, the amount of money being spent could yet increase.

The council has already commissioned an external review, which is being undertaken by David Bowles, an expert adviser on public sector governance.

However, Mr Bibby said there would be a lack of confidence in the report "initiated and paid for by Renfrewshire Council" and called the watchdog needed to get involved. 

READ MORE: Dargavel Primary 'too small' after council blunder

In his letter, the MSP said the cost of new building and the extension to the secondary would “fall on Renfrewshire taxpayers rather than by the developers.” 

“This includes the capital cost of a new primary school for Dargavel, as well as the costs of expanding Park Mains High School in Erskine, which requires enormous alterations to accommodate up to 2000 pupils, making it one of the largest schools in Scotland. 

“It should be noted even the £75m is merely capital costs, and does not include the ongoing costs of teachers and myriad other staff. In sum, as a result of the Council’s catastrophic blunder, Renfrewshire taxpayers are set to pay the equivalent of approximately £421 each for every man, woman and child in Renfrewshire. 

“The situation is thus calamitous not just for Dargavel, but for each and every resident – and especially school child – in Renfrewshire.“

“The former Cabinet Secretary for Education told me she ‘hadn’t seen anything like it’ and I agree.

“A ‘review’ that has been initiated and paid for by Renfrewshire Council is ongoing. However, I believe it is highly questionable whether the current review commands public confidence.

“Given the sheer scale of the blunder and the fallout from it, I am writing to request again that Audit Scotland begin a full independent investigation into this situation and its fallout at the earliest opportunity.”

READ MORE: New primary school to be built in Dargavel after council blunder

A council spokesperson said: “The Chief Executive of Renfrewshire Council last year requested an independent external review be undertaken to understand and learn from the full circumstances of the roll projection error at Dargavel Primary School.

"The review is being led by David Bowles, who brings considerable experience of leading significant public-sector reviews. His findings are due to be reported to elected members in June.

"To date, he has undertaken extensive interviews with groups including current and former council employees, elected members, and members of the Dargavel community.

“The Chief Executive engaged Audit Scotland in relation to the planned independent review and its remit at the time, and they confirmed they were comfortable with the approach.

"They also confirmed that once published, they will review the independent report, its findings and any subsequent actions taken by the Council. We continue to brief Scottish Government on the matter.”

An Audit Scotland spokesperson said: "An independent review into Dargavel School is currently ongoing. Until this independent review is complete, no decision can be made about what, if any, further audit work is needed. "