The head of the Financial Conduct Authority has rebuffed concerns that the introduction of new listing rules for sovereign-controlled firms – widely seen as an attempt to lure the world's biggest ever flotation – would weaken investor protection and harm London's leading reputation for governance.

Nicky Morgan, who heads the Treasury Committee, and Rachel Reeves, her counterpart at the Business, Energy and Industrial Strategy Committee, last month wrote to FCA chief executive Andrew Bailey asking for an explanation about the proposed changes.