Andrew Bailey refused to tell MPs on the Treasury select committee exactly how much extra money was needed

Some of Britain's banks need more capital, the UK's top banking supervisor told MPs, but stressed the government has not been asked to put cash into bailed out Royal Bank of Scotland or Lloyds Banking Group "at this point".

Appearing before the Treasury select committee, Andrew Bailey, who was last month named head of new banking regulator the Prudential Regulation Authority, refused to say how much capital was needed.

The Financial Services Authority (FSA) has been reviewing the capital cushions of all the major banks, and the regulator will provide an update on the health of the banking industry at the end of this month through the Bank of England's financial policy committee.

Andy Love, an MP on the Treasury committee, said it had been suggested that the "order of magnitude" could be somewhere between £20bn and £50bn for the amount of capital banks needed.

Bailey replied: "I agree... there is a need to strengthen the capital position, but I'm not going to get into where the number is."

Love said there had been talk as to whether the government would be forced to inject fresh capital into RBS or Lloydsbut Bailey said of the two banks: "I can assure you I have not asked the government to put money in at this point."

At the hearing, Bailey turned his fire on "ever-more detailed" European Union rules in the area of financial regulation. He said that while it was necessary not tocome across as very anti-European," one of the biggest threats faced by UK regulators was that "there is a different sort of trajectory among many involved in the EU processes who want to create more and more rules."

Bailey also confirmed that Britain's insurance industry had spent "several billion pounds" preparing for new European rules , which may not be implemented for several more years. He said the costs had "snowballed".

Bailey said he was "staggered" to arrive at the FSA in 2011 to discover that it had budgeted for between £100m and £150m to implement the insurance directive. He said these costs had been scaled back, and that while more than £60m had already been spent, he was hoping to bring this headline figure down to between £80m and £90m.