The chief executive of the largest UK insurer, Aviva, has come out fighting in the wake of criticism over the firm's failed GBP17 billion bid for rival Prudential.

Opinion is split on Aviva’s surprise refusal to continue its efforts to buy Prudential. Some analysts suggest that CEO Richard Harvey was disciplined in not going back to the Pru with a better offer after the latter flatly rejected the initial approach.

However some institutional investors in Aviva are thought to be unhappy with Mr Harvey’s role in the affair, with some calling the failure embarrassing, according to a Financial Times report.

There is also a fear that the collapse of the move could leave both Prudential and Aviva targets for acquisition from overseas, with Axa and AIG rumored to be interested in the two.

However Mr Harvey has robustly defended Aviva’s position:

You could not be less vulnerable than we are right now, he was quoted as saying.