The man who was asked by the government to come up with reforms to make the banking system safer, believes the Bank of England’s bank stress tests aren’t exacting enough and need improving.
Sir John Vickers, who lead the Independent Commission on Banking, has also told ITV News that, nine years after the financial crisis, progress to ensure the banking system is more resilient has been "really disappointing".
You may recall that just before Christmas the Bank of England published its annual health check of the British banking system.
Our seven biggest lenders were subjected to a series of tests to establish how they would perform in the event of an economic shock worse than the one we experienced in 2007/8.
Royal Bank of Scotland failed the stress tests and was forced to strengthen its balance sheet. HSBC, Lloyds, Santander and Nationwide passed while Barclays and Standard Chartered scraped through.
At the time, the central judgement of the Governor of the Bank of England, Mark Carney, was that the public could be reassured that our banks are now strong enough to continue lending to households and businesses, even in a severe downturn.
But Sir John Vickers questions that assessment. He is calling on the Bank of England to make its stress tests "more rigorous, more robust".
Sir John says the stress tests are based on the "book" or accounting value of a bank's assets and not the "market" value.
He points out that the share prices of some banks have fallen recently, suggesting investors have some doubts about the quality of some assets.
"Look at what the bank shares are worth" he told me in our interview. "In normal times you might expect the market value to be well above book value. But where we are at the moment, we're at the opposite.
"The market values tend to be below the book value - not for every bank but for some banks and some much more than others. And that, in my view is telling you something, indicating an issue, a concern".
Sir John told ITV News that his "back of the envelope calculation" suggests that had the Bank of England carried out market-based tests "a couple of big banks" would also have failed.
He proposes that in future a market based test is run "in tandem" for "richer analysis".
You may be wondering what all the fuss is about.
After all, the markets failed to spot the last downturn coming.
Sir John argues that while share prices greatly over-estimated the value of banks in the run-up to the financial crisis they adjusted quickly as it approached and in that sense did a "better diagnostic job" than the regulators.
"Clearly markets are not perfect, clearly regulation is not perfect and it’s good to see both in parallel," he says.
Last week Andy Haldane, the Bank of England's chief economist said the failure to predict the financial crisis was a "Michael Fish" moment. Sir John Vickers is more forgiving.
"Forecasting crises is a mug's game, nobody's good at it," he told me. "The really important point is that the Michael Fish analogy, I fear, misses is about readiness. A storm is going to come, we can’t' predict when but you want to be ready for it...we need to do more and when the next severe storm comes, who knows when, we will be in a better position than we are currently".
Sir John Vickers has been critical of the Bank of England's approach to regulation previously.
A year ago he raised concerns about the amount of capital it was requiring the banks to have in funding to protect against future losses. He felt it was inadequate, his feelings haven't changed.
Almost a decade after Northern Rock collapsed into the arms of the taxpayer, Sir John Vickers believes that the banking system, while safer than it was in 2007, isn't as safe as it should be and that progress on reform, much of which his inquiry proposed, has stalled.
We asked Kevin Dowd, an economist and Emeritus Professor at the Durham University Business School, to retest the banks using the market-based values that Vickers proposes.
The result was that three of the big four banks failed. HSBC, Barclays and Royal Bank of Scotland all fell short of the pass-standard of 3%. Only Lloyds passed.
Sir John Vickers wrote to the governor of the Bank of England, Mark Carney, on December 5th to express his concerns about the limitations of the stress tests and urged him to consider including a market-based test.
The Bank of England declined to comment on the issue although it stands by the credibility of the stress tests in their current form.
Mark Carney is due to appear before the Treasury Select Committee to answer questions about the recent Financial Stability Report on Wednesday.