Up to 10 former HBOS executives could be banned for ever working in the City again, after a damning report into the £20bn bail out recommends an investigation.

City watchdogs will now look at taking potential further action against former senior management after a report by Andrew Green QC blasted former regulator the Financial Services Authority (FSA) for its failure to investigate a raft of top bosses.

Only one former HBOS executive, Peter Cummings, has so far been formally investigated and fined.

The long-awaited report concluded that ultimate responsibility for the failure, which led to a takeover by Lloyds and a bail out of more than £20 billion of taxpayers' money, rests with its Board and senior management.

They failed challenge a risky and "flawed business model" which relied on continuous growth, the Prudential Regulation Authority (PRA) and the Financial Conduct Authority (FCA) found.

James Crosby, the bank's chief executive during its period of rapid growth, was formally stripped of his knighthood two years ago at his own request after a scathing Westminster report into the downfall of the Scottish bank.

The Parliamentary Commission on Banking Standards claimed that he had been the "architect of the strategy that set the course for disaster".

But only one former executive has been sanctioned by the FCA in the wake of HBOS.

The publication of the 500-page report into what went wrong had originally been expected in 2013.

It has been made public alongside the inquiry into regulators' actions following HBOS' collapse.