To ask how to resolve this!

He is keeping the uniforms deliberately so you have to beg for them back and buy new ones, it’s a control tactic and he’s controlling the nights he has them too. He has said you are hassling him, yet he deliberately causes problems so you have no choice than to contact him. He doesn’t want you ringing his family incase they help you, he wants you to feel totally helpless over his control.

CAFCASS should listen to her. They might not agree to her not seeing him at all but will advise the Court of what she has said and why.
They may not recommend yours or her perfect solution but the Court will order what is best for the children, not just what he wants.
I think a pp suggested a co-parenting app too which is a good idea.
Sorry, slow fingers, that was in response to OP's previous

Sorry OP I've only read your responses so others may have mentioned this.

I would talk to school and let them know what's going on, and ask them if there is anything they could do to help.

Practically speaking could you:

• send them to him on Sunday with nothing but what they are wearing
• arrange to leave a PE kit and uniform at school on Friday and see if school would facilitate your child changing into that PE kit first thing Monday morning then allowing them 5 minutes at the end of the day to change out of it, similarly would they then allow 5 mins at the start of Tuesday to allow your child to change into the school uniform you left for them at school
• then when you do Tuesday school pick up you get your PE kit back ready for later in the week or washing if needed, and you haven't lost a uniform

(And if he does Tuesday pick up then similarly ask school if they will allow 5 mins at the end of the day for your child to change out of the uniform you've provided and leave in a bag for you to collect on Weds).

The worst the school can do is say no, but if you discuss it with them they may be able to help.

She's now of an age where, if you go to Court, CAFCASS will listen to her.

No, it's too much to put on an 8 year old. My bet is they hate going there anyway - this would make it even more stressful.

I think you have to maybe get the 8 year old to be responsible for both of their uniform. Say that we are sending you with this many of each thing and those things all must come back. Even remind them just before they're due to leave his house.

I'd say tell the dad to be more careful but he sounds like he won't bother!

He's controlling you psychologically and financially by his actions. His failure to disclose his address is not selfishness is it?

what an arse

I would stop sending any pe kit there or uniform - and tell school what is happening.

Could they keep PE kit in school? or do you live near school and could bring it on for them ?

That's great but don't hesitate to go through the courts if he won't play ball. One step at a time and you will get there.

A dad who takes his kids' uniform from them and keeps it from them so they can't have it.

Why?! Why would you take your kids' clothes? I don't understand what he's doing with it!

Because he’s being controlling

He’s managed to convince you not to contact any of his family by accusing you of ‘harassment’.

He’s purposely withholding his address and claims it’s because ‘you are a psycho’, and thinks anything you do to stop his behaviour is because you ‘love him’, despite you being the one who walked away from the relationship.

He knows full well you don’t want him and that there is no harassment. He’s trying to gaslight you into believing that you are the problem, so that you don’t question him or challenge him.

Of course this is abuse. You don’t recognise it as abuse because you have, over the years, been conditioned to accept is as him merely being selfish.

Talk to Women’s Aid.

and read WHY DOES HE DO THAT by Lundy Bancroft. Free pdf online.

Talk to Women’s Aid and CAB.

Write a detailed, factual timeline of events post-divorce and see an experienced family solicitor, with a view to getting him to agree to mediation. Maybe, hopefully, a formal, legal request will be more effective than your own past efforts.

If this fails, and I fear it will, you absolutely need to take him to court. You cannot, simply cannot let this drag on for the rest of your children’s childhood.

You're not going mad, you're being abused. But what are you going to do about it? You've been advised by several people to go through the courts. I get that you may feel paralysed as he has so much control. Is there anyone IRL to support you if you are struggling to act?

Do you drop them off at his house? If so insist on getting all their clothes back then If he doesn't like you nagging tough shit. or send a bill with the children for the missing clothes.

You can let that happen. He knows that you will choose not to.
Speak to the school, send them without uniform. When he sends them in to school in dirty, mismatched uniforms that’s on him.
Then they can change into the clean uniforms you have left with the school.

What? You don’t know where your kids are when they go to his house?

No, no. Stop all this right now. He’s taking the piss and running rings around you by coming up with this ‘harassing him’ bullshit.

Off to court you go and get some firm rules put in place.

He shares his address so you know where your children are, he returns the uniforms he has at his house and he has them on weekends going forward. Otherwise they don’t come to see him at all.

Ahhh - so he isn’t just being a disorganised melt, it’s point scoring to get a rise 🤷‍♀️

If it’s a court arrangement request order updated with no overnight stays as he refuses to return with clothing or disclose address