Originally Posted by
Often1
The chances that you will be admitted to the UK are zero or worse. "Public security" is a broad-based exception to your Right of Movement and a conviction for a crime which actually involved a prison term fits right into the exception. You also need to realize that your conviction in the UK will affect your ability to travel elsewhere as well, although you will need to look at exactly how "public security" or its equivalent is handled.
To the contrary, the chances that you will be denied entry to the UK are very slim (with the caveat below). There are still perfectly legal routes into the UK as an EU national (eg. travel to Dublin and take the ferry to Wales) which have zero routine checks. Until you have been served with/notified of an actual exclusion decision/exclusion order, your Right of Movement remains in place, regardless of previous criminality.
Now, if the OP was removed under the FRS (Facilitated Removal Scheme), then they would have received notification of the exclusion decision at the time of being granted their release under that scheme. If so, the exclusion would usually be for the period of 24 months from the date of exit (unless otherwise varied and notified at that time).