Spreadsheet modelling errors are being blamed for the botched bidding process on the £9bn West Coast Main Line rail franchise contract.
The unravelling of the franchise bidding process was the result of frenetic legal and political lobbying last week. But informed sources pointed their fingers at a flawed Department for Transport (DfT) forecast model as the main reason for its humiliating and costly U-turn.
The four bidders will be refunded a total of around £40m; with three other franchise bids put on hold, the ultimate cost to the taxpayer could rise to as much as £300m.
After awarding the contract to FirstGroup on 15 August, the department faced a very public counter attack from current franchise holder Virgin Rail.
Virgin commissioned specialist...