For years there have been concerns that the big banks are a little too cosy, that they are so big they have a stranglehold on the market and, as a result, are not serving their customers as well as they should be.
The Competition and Markets Authority has spent the last four months looking at the market share of Lloyds, Royal Bank of Scotland, Barclays and HSBC in particular.
My understanding is that tomorrow morning the CMA will order a full-blown investigation into personal current accounts and business lending - one that may conclude that some banks should offload parts of their business.
The former chairman of Metro Bank welcomed the news. Anthony Thomson is in the process of launching a new bank next year but says there's "virtually no competition" in the current account market.
What's interesting is that this is happening at a time when new banks are springing up and existing players, like Virgin and Tesco, are wading into the current account market.
Last September saw the introduction of the seven day switch guarantee. In theory it's never been easier to change banks, in practice relatively few of us do.
Banks say that because we're happy. Consumers groups, business groups, politicians point to the number of complaints.
In April the Executive Director of Which? told ITV News he wanted the big banks, like the big energy companies to be subjected to a full, independent investigation.
Tomorrow he'll get his way.