The UK's exit from the European Union could end up costing banks up to $50bn in capital costs to support new EU subsidiaries, according to a new report from consultants Oliver Wyman.

The report paints a worrying picture of how a "hard" Brexit, in which banks lose their automatic right to serve EU customers from London, will lead to a lose-lose scenario for banking in both the UK and EU, with regulators insisting that the new EU subsidiaries currently being set up by banks become more substantive over time.