Through a letter to his solicitor,
For eg,
"Dear .......
Further to your recent letter, I would like to reiterate my posistion in considering the access rights that ex dp is attempting to enforce.
Ex Dp has continued to make attempts to see his DD through the courts and now through you over a course of three years and to date has not contacted myself directly to discuss suitable arrangements.As it is, I decline the proposal that ex DP have DD overnight on a regular basis
However, I do believe that it is in my daughters best interests to have contact with her father and for that ex DP and I come to an amicable arragement for him to see and get to know DD and I do not believe that 6 supervised visits qualify my ex DP to have my daughter overnight. However, if and when ex DP contacts me to make such arrangements, we can also discuss the possibility of this in future should my daughter so wish.
.................
I think if you say something like this, no-one can say you are being unfair