Owner rights of access after tenency agreement expires

Hi belegal team. We're a small property management and lettings agency on the Costa Blanca. One of our tenants, now on the second 11 month rolling contract in a furnished 3 bed, is two months behind with the rent and is refusing to pay utilities (which they agreed to do as part of the tenancy agreement). I have noted your comments about the 'futility' of pursuing tenants for debt recovery. However, my question is this.

The tenancy agreement expires at the end of this month. Can the owner (or ourselves as letting agents) have legal access to the property once the agreement has expired and remove any of their effects or do the tenants have any legal right to remain in the property. I am taking a conciliatory approach to resolving this amicably with the tenant, although they no longer answer my calls, do not reply to my texts or letters delivered to the property. Any advice and guidance would be greatly appreciated. Many thanks. Nick