What To Do - By Ex Offender

Hi.. I am an ex offender actively seeking work and have come across some obstacles. My conviction was for theft and I have disclosed this conviction on two interviews. Needless to say that I never even got a letter, never mind a phone call saying that my applications had been unsuccessful. I am fighting with the decision, do I be honest with the employers, or do I not mention my past conviction? I don't want to settle in to a job and then the employer finds out about my past and lays me off work for being dishonest? I am just in a maze of what to do. It is alright for the likes of the probation service and prison service to waffle on about finding work as part of a resettlement programme, but what about this kind of situation that I and probably many other ex offenders are going through? What to do? Regards, Dave.