Originally Posted by Unregistered

Since you are fresh grad, of course they'll look at O and A level certs... these are your only track record so far.

Don't worry so much, as they have already called you up for interview, I think the face-to-face counts more. Don't let the worry affect your interview, and appear confident and eager to take up the job. Read up more about the dept and current policies relevant to it. Be prepared with some opinions (not too far off the official positions, of course!)