Can Ex-Clerics use divine magic items?

[TheEvil]

The title pretty much says it. It is in a living campaign which requires that all clerics have a deity, the loss of status would be due to alignment change.

I don't think so, but it seems to be something of an open question...

 

[dcollins]

From SRD:

Ex-Clerics
A cleric who grossly violates the code of conduct required by his god loses all spells and class features, except for armor and shield proficiencies and proficiency with simple weapons. He cannot thereafter gain levels as a cleric of that god until he atones (see the atonement spell description).

Using spell-completion and spell-trigger magic items (what you're basically asking about) both counts as a class feature, and is predicated on having a legitimate spell list. It's definitely lost.