Tenant who is leaving is stalling on allowing showings

[Robbie McCarthy]

Anyone had this issue with NJ rentals and know our landlord rights? tenant did not notify us of his intention to leave at the end of his agreement  on 3/22 - we found out because they posted about their new home on FB!  Anyway we have a ton of interest from our advertisement,  so we set up open house viewings for this weekend Sat and Sun 11am-2pm. Tenant agreed. I set up all viewing appts. Now tenant saying they can't allow it as wife is ill.....dubious based on their history. What rights do we have for access and showing new prospective tenants around an occupied rental? Sure this is not unique.