Can he take my children?

Nope. The kids are entitled to a relationship with people but adults are entitled to anything.

From a legal standpoint if you’re in the uk and he is on the birth certificate he can take them aslong as he isn’t leaving the country. I’d get some proper legal advice

If he is discussing separating assume that is where you are going. Seek legal advice. Get custody settled immediately. Moving them is a bad idea, if he is thinking it is not he is not making rational decisions.

It is tricky as you both have rights but I would say don’t let him go and take them once you do it is harder.

the 8 hours away is too much so seek legal advice now and start the process

yiu have equal rights remember and the status quo tends to be preferred to him moving if that makes sense

You need to get legal advice. You may be able to get a prohibited steps order but no way can strangers on the internet advise you re this.

Is this for a visit or to move house?

You need legal advice.

As their parent he has the same rights as you do and can take them to see his parents in the salt country if he wants to.

You need a solicitor. Today.

What’s your current living situation? Does he have parental responsibility? Are the children registered at nursery? Is his depression being treated by his GP, is he on any medication?

Reading between the lines of your posts the fact that he wants to remove the young children from your care and take them eight hours away is not a normal, well adjusted thing to suggest. It’s a red flag. I would assume this relationship has been unhealthy. Has he been emotionally or physically abusive to you?

As others have said, go to court for a CAO.

If he's on the birth certificate yes as he has same rights as you. If he's not then no not without a court order. Assuming you are in UK of course I appreciate things may be different elsewhere.

Neither of you have more or less right than the other to keep the kids in your care. Who does most of the care currently? Do either of you work? What's the situation with the house - are either of you planning to move out?

Without a court order in place he has just as much right as you do to take the children to visit family within the same country.

What you need is a court order that states who in the resident parent that the children reside with and so.

Otherwise either of you could take the children, refuse to return them. The police won’t get involved. You’d have to go to court.

Poor kids!

He is of course as entitled as you are to fight for custody. You need to put your children's needs at the centre of your agreement. One of you is probably going to have to move as I can't see a true co-parenting relationship working when you are 8 hours apart.

If he is on the birth certificate he has parental responsibility so he can remove them. You might need to get an urgent court order for residency if you think it unreasonable or unsafe.

I think if the kids are big enough to lift and put in a car I'd be seeking legal advice now in advance so you know what you can do to protect yourself.

Has he ever been abusive towards you or to the children? If you feel he's unfit to parent because of his mental health then you need to contact social services and get them involved so they can assess his capacity to parent. Unless there are significant issues with your own parenting I don't see any court or social worker thinking it's a good idea to move two toddlers 8hrs away from their primary caregiver by an unwell parent.

What country are you in and why does he want to take them away from you? You have parental responsibility by virtue of being their mother. Is he on their birth certificates?

Are you saying your children at risk under his care?

If you tell him to take you to court then that will buy you some time. He can ask for up to 50% of the time (I assume you live near each other so he can do the school run etc ) You can’t stop him living with his mum or the kids having access with his mum during his time

If you're separating or on the edge of it I would not want him taking the children if you think there's any possibility of him not returning them. You need to agree a custody arrangement detailing where the kids will stay and when and that should be centered around what is best for the kids. Which may be staying in what they see as their own home with regular time spent with dad. How old are your kids?

I'd speak to a solicitor for legal advice who specialises in family law and domestic abuse. You could also report him to social services and seek support from womens aid if you feel he's being abusive.

Has he stated if he sees this being part time or for how long? What's the bedroom arrangement at his mums?

The fact you're unmarried is irrelevant you're both the children's biological parents and you both have to make an agreement. One parent can't unilaterally up and leave with the kids and if they do the other parent could take them to court.