FCA chair Charles Randall has warned that the UK will be unable to manage the risks of financial crime under a no-deal Brexit, emphasising the critical role played by cross-border data sharing agreements with EU member states.

Speaking at the watchdog's annual general meeting, Randall says that by the start of the Summer, the UK had routed some 3.1 billion transactions reports to other EU authorities via the European transaction reporting mechanisms.

"Whatever shape Brexit eventually takes, maintaining and deepening our partnerships with international regulators and law enforcement agencies will remain vital," he says. "It is important to stress that we cannot manage the risks of financial crime successfully unless we can share data in this way. Data sharing provides both the UK and EU countries with a vital foundation to tackle cross-border market abuse, including insider dealing and cross-market manipulation."

UK negotiators in Brussels are wrangling for preferential treatment over other other non-EU bodies post-Brexit, warning their EU counterparts of significant threats to economic security from a break in data sharing deals.

With negotiations still up in the air, the FCA has earmarked £30 million to its EU withdrawal budget as it prepares for the UK's exit from the union.

"Our business plan for the next year explains that we will continue to devote a considerable part of our resources to Brexit," says Randall. "I think it is important to say that meeting this funding requirement has required us to take difficult decisions elsewhere."