A secret file containing details of the pornography on Damian Green’s computer was preserved by police despite a command from senior officers that the data should be deleted.

The disclosure raises the prospect of decisive evidence coming to light — and is likely to further widen divisions between police and MPs. Senior Downing Street aides are now understood to want Green to resign, rather than forcing Theresa May to decide whether to sack or clear him.

Gavin Barwell, the chief of staff, is among the aides who believe Green should do the “decent thing” and “fall on his sword”. The Cabinet Office is carrying out an inquiry into Green, who is also under investigation for alleged inappropriate advances to the academic Kate Maltby.

The government