Ashurst and magic circle trio Clifford Chance (CC), Freshfields Bruckhaus Deringer and Linklaters have each been retained by the big four high street banks after the Competition and Markets Authority (CMA) launched its investigation into the current accounts and small business banking market last week.

The firms were originally instructed by the banks in July when the CMA first began a consultation process reviewing alleged lack of competition into the market with a view to launching a formal probe.