It's about leverage in the power sense, rather than financial. If systemically important banks are outside the EU's jurisdiction, and that jurisdiction lets the

It's about leverage in the power sense, rather than financial. If systemically important banks are outside the EU's jurisdiction, and that jurisdiction lets them fail, it could hurt EU member states more than the foreign jurisdiction. Thus banks that are systemically important to the EU must not be outside the EU's supervision, one way or another - in direct opposition to May's obsession with sovereignty. The UK's sovereignty will need to be traded away to get any alternative free trade deals in any case, but UK politicians have been too cowardly to make that case to the public, so the fact that nothing is really going to change much on the red tape front hasn't sunk in yet. You can't trade without agreement on standards, and to get multiple parties to agree, you need one of those nasty globalist organisations involved.