Communication and boundaries. You need to decide whether or not this is something you are willing to live with. If not, communicate what you need to see. If your partner does not respond, you can try enforcing your boundaries. If you're still living in a laundry heap after that, it's up to you to decide if you want to end things, or share your life with someone who is not going to respect your boundaries. (I wouldn't.) Sounds like you've already done the communication bit, so what's got you in denial about the lack of respect? Don't think about the relationship you wish you had, look at the relationship you have. Is THIS what you want?

I'd also personally be concerned with spending patterns that don't reflect a reasonable need or occasional luxury.

EDIT: 'jet' has a suggestion on totes that is a decent suggestion on what enforcing your boundaries might look like. There's a difference between interdependency and codependency, and sometimes we or our partners need help. Your partner's response to the enforcement of your boundaries will be telling.

Yea my wife had a clear out, then started buying more as she had space.... I bought 2 big vacuum pack bags, so she has to rotate out summer and winter clothes. This give her a hands on look at what she has as she rotates her stuff out.

2 possibilities:

a) They're just inconsiderate or don't realize it... Communicate. State your perspective. Make them realize the situation and make it clear how this affects the both of you. You could set boundaries and enforce them. For example agree on a confined space for the clothes and they can do whatever they want within that space but not exceed it.

b) It's a psychological issue / mental problem. For example they could be a hoarder. You pretty much can't do anything unless you're a psychologist. This needs therapy.

Maybe start with making them realize the situation. Make sure they understand. Help them by teaching them how to handle their belongings and how to decide what to keep and what isn't needed. Follow up with a clean-up day and help them to get rid of the excess. Give it to charity. Make sure boundaries are in place for the future. Be kind unless prompted to be strict and enforce what you've agreed on. (And properly agree on rules together. It doesn't work if it's your rules. You have to come up with the rules together.)

Reading the replies with interest, partner moved in with me to a 4 bed house. 1 room is now a closet with 4 wardrobes 3 chests of drawers, and two giant bookcases full of shoes, and no floor space left. 2nd room is full of boxes of clothes, and she on at me to build a new quad wardrobe in there. Then we have my office which is storing all the non-clothes items from all the other rooms, and our bedroom with 6 wardrobes and two chests of drawers all full to bursting. Clothes and shoes count is easily in the 1000s. I have one pair of jeans and 10 t-shirts on rotation. She keeps buying me stuff too that I never wear. She keeps saying people need clothes but I’m just here to say OP, it could be worse.