The Financial Services Authority (FSA) and John Tiner, the new chief executive of the UK regulator, have publicly defended themselves against claims that stringent new rules on solvency will force mutual insurers such as Standard Life to float or sell themselves against their will.

In a public letter released ahead of a parliamentary debate on Wednesday about the UK insurance industry, Tiner insisted that it was the job of the regulator to ensure that Standard Life and other UK insurers have enough capital to meet their financial obligations and treat their customers fairly.