The problem is not with the children. It is between you and your husband.
You and their dad need to sit down (without the kids around) and establish some rules and the punishment for disobeying those rules. Do this ASAP. Once you have done that, the two of you should sit down with the kids, everyone together. Go over the rules and punishments. You then need to follow through with what was decided upon. If you don't, it will let the kids know that they don't really need to follow the rules because if they break them you will just ignore it anyhow. They need to see consistency.