David Cameron has joined the same public speaking agency that has helped his friend George Osborne earn £500,000 since being sacked as chancellor.

Tony Blair and Gordon Brown are also clients of the Washington Speakers Bureau, a company that regularly finds business audiences willing to pay six figure sums for speeches.

Parliament's Advisory Committee on Business Appointments (Acoba) gave cleared Mr Cameron to start working with the WSB in September.

On its website, WSB describes Mr Cameron as "one of the most prominent global influencers of the early 21st Century".

In its profile of the former Prime Minister, it says Mr Cameron can provide, "lessons in leadership at an extraordinary and turbulent time in global affairs - not least on building economic strength; creating inward investment across the UK and Europe against the backdrop of an emergent Russia and China; and navigating complex international security challenges".

His pivotal role in the EU referendum means Mr Cameron also offers, "an unrivalled perspective on the future of the European Union and Britain's place in the world following Brexit; and a unique insight on the rise of populist politicians and parties at a time of profound global change."