In the six years since the banking crash ushered in a recession across much of the world, bankers have not done as much as might have been expected to clean up their image and mend fences with a disgusted public.

At the same time as the senior executives of behemoths like Lloyds and RBS have been putting on their contrite face in front of stern-faced MPs, one further banking scandal after another has erupted: mis-selling, interest-rate rigging, even money laundering; the list goes on. It never seems to end and the lessons never seem to be learned. Only this week, Lloyds Banking Group was fined £218 million by UK and US authorities for rate rigging. The Bank of England governor, Mark Carney, said such manipulation was "highly reprehensible" and "clearly unlawful".

Members of the public have a variety of other names for it. What is clear is that not enough was done in the aftermath of the crash to rein in unscrupulous executives.

Well, now the Bank of England is attempting to make up for that. Its Prudential Regulation Authority has introduced a new regime under which reckless bankers will have to pay back their bonuses up to seven years later, even if they have spent the money; that could be extended to 10 years for senior executives under certain circumstances.

This is a commendable move, albeit long overdue, which recognises the depth of public anger about how unscrupulous individuals have until now seemed largely untouchable. Some of the worst behaviour has been at taxpayer-owned or part-funded banks. However, one obvious shortcoming of the measure is that it will only apply to bonuses paid from January next year.

Given that so much damage relates to bankers' past behaviour, this is far from satisfactory. The Bank of England has indicated that trying to apply the rules retrospectively could open it up to legal challenge, and this is almost certainly true (well-paid bankers are unlikely to have much trouble hiring expensive lawyers to fight their corner) but it leaves unresolved a number of great wrongs. It also remains to be seen how straightforward the new rules are to enforce and how much will there is to enforce them.

Predictably, many bankers' representatives have criticised the move, using the well-worn line that it could undermine the City's competitiveness and cause "talented" people to go overseas, but it is heartening to see the country's central bank calling their bluff on that score.

This has been billed as the toughest restriction anywhere in the world on the banking sector's bonuses, though in truth there is not much out there in the way of competition. And there is more to come: a consultation was launched yesterday on introducing a new approval regime for the most senior executives in banks and a further certification regime for other staff.

It is all a lot better than nothing, but whether it works as a way of cleaning up the banking industry will depend to a great degree on how much will there really is to tackle the rot.