Shadow Home Secretary Yvette Cooper has questioned whether Theresa May authorised the leaking of a letter she wrote to Education Secretary Michael Gove.
Did the Home Secretary authorise the "improper release of correspondence between Ministers" that the No 10 statement refers to?
The private letter appeared in the media and seemed to show Ms May questioning Mr Gove's handling of alleged extremism in some Birmingham schools.
The leaking, from her department, of a letter to Michael Gove, raises serious questions for the Home Secretary to answer.
One school was praised by Ofsted for using money from the pupil premium to pay for a number of cultural trips to Saudi Arabia.
Six Birmingham schools will be rated 'inadequate' and several more downgraded. Council officials have been criticised for failing to act.