HM Revenue & Customs chairman Paul Gray has resigned over a security breach allegedly involving 7.5 million child benefit claimants.

There are no further details at this stage though rumours suggest the situation may have been kept under wraps for the past week or 10 days.

Chancellor of the Exchequer Alistair Darling is making a statement to the House of Commons at 3.30pm.

Treasury committe chairman Michael Fallon is reportedly "stunned" by Gray's departure.

Gray's letter to HRMC staff reportedly gives the reason for his departure as "a result of a substantial operational failure in the department".