Millions of pounds will be spent on six modular classrooms at a Renfrewshire school after a short-term fix for capacity issues was approved.

A review has been ordered over botched sums which sparked serious concerns about the size of Dargavel Primary less than a year after its doors opened.

Renfrewshire Council is seeking a permanent solution to the problem, with a report to be put before elected members in the early part of next year.

In the meantime, the modular classrooms – each of which will have room for up to 198 pupils – will be introduced at the Bishopton school over the summer break, at a cost of around £2million.

The capacity blunder emerged after analysis suggested space could be needed for as many as 1,100 pupils in the years to come – double the school’s preferred maximum of 548.

It is estimated that the school roll could rise to as much as 620 by August next year alone, despite initial calculations predicting the register would not exceed 430.

A special meeting of Renfrewshire's education board took place today to discuss the issue and approve the short-term fix.

Councillor Emma Rodden, education convener, told colleagues: “I want to assure you that my priority is to find a permanent solution that provides the best learning environment now and in the future for all children in Dargavel Village.

“I’m very sorry for the upset that this is causing parents and carers. I also want to mention the headteacher Gerry Carlton and the school staff, who I know have your support.

“I am conscious of the impact of the publicity surrounding this issue on them too and I want to extend my sincerest thanks to them for everything they are doing to reassure the school community.”

Councillor Rodden said the “input and expertise” of educators and support staff will be “invaluable” as the local authority works towards a solution.

She added: “This mistake made is significant, to say the least, and I am asking colleagues in attendance to work collaboratively to ensure we can find a solution quickly and in partnership with the school community.”

Elected members agreed that any probe into the blunder should be an “external inquiry.”

Councillor Rodden said: “This review will establish what went wrong and why and will provide actions that we as a council can take to ensure that a mistake of this nature will not happen again.”

A council report confirmed research based on the current roll, the known pre-school population within the catchment area and the potential pace of housebuilding in Dargavel Village, which is expected to have 4,000 homes by 2034, had found existing capacity would be “materially insufficient” to meet future demand.

The document also detailed that the original methodology used to project the roll was “inadequate” and “significantly understated” the scale of capacity needed to support primary education.

Councillor Gillian Graham, the Labour group's education spokesperson, claimed the error could end up costing Renfrewshire taxpayers a whopping £20m and said the blunder was “entirely due to this council’s mismanagement.”

She also accused the SNP-led council of “a dereliction of duty" on the project over the last five years.

Steven Quinn, the council’s director of children’s services, has apologised to those affected by the situation.