I live in Ontario.
I have 2 daughters 13 and 11.
I have been separate 6 years.
There is a court order for the children to see their dad Wednesday and every other weekend.
The children have never like being with him.
I have always encourage them to spend time with him even thought I know
They hated going.
Lately now that they are older they are refusing to go.
I really don't want them with him as he is not a stable individual but not bad enough
To report.
Do the girls have any rights NOT to go?
And if they have to go with him how do I explain it to them?

In the US, they have no right to decide. However its pretty hard to force them also.

I don't have much sound advice for you other than to try to convince them that no one really has a choice.

If the girls refuse to go, he can go to court to enforce the visitation order. If he does, then you have the girls explain to the judge why they do not want to go. The judge will then decide if a modification of the order is necessary.

I usually agree with Scott, this time is no real exception. The only thing I would add is I can't see a way to enforce the visitation order in this instance. If he shows up and the girls don't want to get in his car – he leaves right? Short of dragging the girls kicking and screaming into his car (and at this point I would call the police and set a court date myself the next day) there is no real way to get the visitation order enforced. Most orders say that visitation will commence at such and such time and last until such and such time with pick up/drop off at CP house. CP will have the children ready at the appointed time and NCP will be there to pick them up. Unless this was a problem in the past the order most likely doesn't address what to do if the children don't want to get in the car and go.

OP – my advice is to reread the order as it pertains to the visitation. If your part in the visitation is to have them ready at whatever time so that he can pick them up always do that. Have the girls explain that they don't want to go with dad then let him decide if he wants to push it or not. If they really don't want to go they will speak up. Maybe after a couple of missed times they will want to go again.