The Financial Services Authority (FSA) intends to recruit an additional 460 members of staff this year as it toughens up its regulatory enforcement.
Setting out its business plan for the 2010-11 financial year, the watchdog said it would be delivering an "intensive" supervisory approach for large firms.
The move comes as the financial services industry is facing pressure to improve transparency and restore public confidence following the banking crisis.
Hector Sants, chief executive of the FSA, pointed out that by its nature, intensive supervision is more confrontational, hence the need for more supervisors.
"If society wants a more proactive approach it must accept that it will have a larger and more expensive regulator," he remarked.
The FSA said supervisors will intervene early if they identify any potential threats to consumers or the wider market.
Last month, the regulator said it would require an overall increase in funding of 9.9 per cent in the coming financial year.