Problem tenant and obtaining possession

Tenancy Deposits

my tenant contacted environmental health because her flat was becoming increasingly damp. The env. health wrote to me formally, and confirmed that remedial work would have to be carried out. I had already arranged for a damp specialist to go in next week to fix the problem.

then the tenant asked if I would grant an early release from the 6-month ast, which I agreed to but she only proposed to give me two weeks notice to leave. I said she could leave, providing she gave me one months notice. She refused and said she would leave after 2 weeks and asked for remission of the 2 weeks rent as 'compensation' for inconvenience she had suffered. She wanted to leave some of her belongings in the flat to collect at a later date though.

I have already emailed and hand delivered a letter to her flat,in which I agreed to an early release from 7 Dec,advising her that I will be collecting the keys from her on 7th Dec. and asked her to confirm her agreement to this in writing.

She hasn't replied and I am worried whether I could be regarded as trespassing if I enter the flat to allow the contractor to carry out the work next week. Or would this be deemed to be within my rights as per the RLA tenancy agreement?