A Cabinet minister has piled pressure on beleaguered First Secretary Damian Green saying it was "not acceptable" if he used a workplace computer to watch pornography.
Education Secretary Justine Greening said it was important to have "high standards" in public life.
Tory MPs have been rallying round Mr Green following claims by two retired police officers that pornographic images were found on his Commons computer during a 2008 investigation into Home Office leaks.
Mr Green - who is also under investigation over claims of inappropriate behaviour towards a woman Conservative activist - has strongly denied downloading and viewing the material on the computer.
Asked on BBC1's The Andrew Marr Show whether it was acceptable to view pornography on a workplace computer, Ms Greening said: "There are clear laws. I think most employers would say it wasn't acceptable."
Ms Greening declined to comment directly on the investigation into Mr Green, but added: "I think it is important that we have high standards in public life."
Health Secretary Jeremy Hunt said he has "confidence" in and "absolutely" trusts Mr Green.
Speaking on ITV's Peston On Sunday, he said: "I do have confidence in Damian Green and I have actually been in a situation Damian Green was in, where you are in the eye of a storm and everyone thinks you've done an absolutely terrible thing and what I learnt from that is that you have to wait until an investigation is completed.
"And I was vindicated at the end of that process in my own case but I think we have to allow the Cabinet Office to complete their investigation.
"I know Damian Green as a colleague and I trust him absolutely and that's why I believe what he says, but there is an investigation... and I think... we should wait."
Mr Hunt described Sue Gray, who is leading the inquiry, as a "very, very capable lady" who has to make a judgment on whether a minister has adhered to the ministerial code.
"I think we have to allow her to make that judgment, but what we can't do is have trial by media and everyone jumping to conclusions when we don't know the outcome of that investigation."