HM Revenue & Customs policy chief Dave Hartnett has been appointed acting chairman of HM Revenue & Customs.

The Cabinet Office confirmed the news, revealed by Accountancy Age last night.

His appointment does not mean he will become full-time chairman, but Paul Gray also carried out the acting role before taking the top spot officially.

Hartnett's move to the top will surprise few in the tax world, where his command of the technical detail has made him an influential policy chief. But permanent secretaries in such roles often also have experience across Whitehall, which Hartnett does not have.

The appointment of Hartnett to the top role would follow Paul Gray's sensational departure over the loss of the personal data of 25 million people.