to expect my ex not to smoke near the children

[chillistars]

Both of my children have asthma, when they go to their father's for the weekend he insists on smoking when he is with them.
Am I being unreasonable to stop them going? Would I be able to legally refuse to let them go? They are 2 and 5.

Nothing constructive to say apart from what a knob ExP is for STARTING smoking recently!

Still think a District Judge would go with it though on health conditions if it came to it. It would then be for dad to challenge on the grounds that smoking is not illegal but that would be costly and , as you rightly say, cause further acrimony.

(sorry for piecemeal contributions, multitasking unsuccessfully here)

lol at CadleCrap, agree entirely.

Chillistars, if I were you I would get the asthma report to give to your ex, then give him a week or two to stop smoking around your children. Only then get a solicitor involved, otherwise if the situation escalates and you end up only communicating via solicitors you will rack up £££s in costs. Children pick up on tension at handovers which is hugely damaging for them. Or course you want to protect them from being damaged by the smoke too, just give your ex a reasonable chance to sort things out because all out war between parents is horrendous.

IMO anyone who smokes around / near children / or inside before they will arrive to visit is being VERY unreasonable

Well if he has said he won't smoke when they are there then give him a chance to demonstrate this. As others said, if he smokes in the garden or whatever then it shouldn't do them too much harm.
Do bear this in mind though: pressuring a smoker to stop smoking is counterproductive. By all means give him the clinic report but don't go on and on and on or start using threats of solicitors. You want to keep the relationship with your XP as amicable as possible, not a battle of wills.