Thank you everyone for your comments. To make things even more complicated the Landlord has asked me to cancel my cleaner on Saturday 6th July as she would prefer to use her own for the end of lease clean on Monday 8th July. She has assured me she will not be moving in herself until after the end of lease clean on Monday 8th, but her Manger for the property has unwittingly mentioned that the landlords intend to hold a party at the apartment on Sunday 7th July, so I guess they are trying to charge me to pay for their cleaner to come the day after their party!
I don’t have any way of proving they will be using the apartment after we leave on Saturday 6th July and before their end of lease cleaner comes on Monday 8th July- other than entering the courtyard using the door code and photographing their gathering in the apartment on Sunday 7th July, but I am sure this would be illegal, so I won’t. Any ideas?
I think I will just keep my cleaner booked for Saturday and make sure the manager includes that the place is cleaned to a highly satisfactory standard at the time we leave. I was told by the owner though that if I use my cleaner and the result is not to a sufficient standard, they will need to still have their own cleaner come on Monday 8th July to “bring the apartment up to standard”!
I emailed a few days ago and told them firstly they can’t pluck a “late check out fee” of 300€ out of the air without any justification (the rent is 2200€/month) and secondly it is not reasonable for them to expect me to pay for their cleaner to do an “end of lease clean” on Monday 8th if they plan to use the place on Sunday 7th July. I haven’t received a reply from them and I don’t expect to.
The Manager contacted me about something unrelated, she wanted to pop over and take a measurement of the oven but during this conversation she also advised that I will need to provide proof of a link to a website about renting in France that shows I have a right to occupy the apartment for the entire day on the last day of the lease before I can expect a reply from the landlords! She also confirmed the landlords have already asked her to book their cleaner for Monday 8th July!!