It is understood that Montague's plan to scrap the PFI in its current form and create a "Government Investment Bank" to finance deals found favour with former paymaster-general Geoffrey Robinson, but was more coolly received by his successor Alan Milburn.
Montague's proposals for the investment bank to arrange funding for PFI projects were put forward as part of a wide-ranging review of the PFI conducted by Sir Malcolm Bates, director of Pearl Assurance. The review findings were to be put to the chancellor before this week's budget.
Montague was widely expected within the construction industry to carry on as head of the new bank or an alternative agency aimed at getting difficult PFI projects off the ground.
Jennie Price, head of the Major Contractors Group within the Construction Confederation, said Montague's decision to leave his post would be a blow. "He's done a great job, he was a very effective leader on the taskforce. There was never any middle management. It was always just Adrian and a lot of younger people who were very good at getting deals done."