If your local legislature doesn't enable the treaty, you aren't bound by it: it isn't a part of your law. A trade treaty is essentially a promise to pass a set of laws.
In the case of the EU, there isn't even a ratification step once the EU commission (which isn't elected) agrees to a treaty.
And of course ... https://en.wikipedia.org/wiki/Supremacy_(European_Union_law)
That means that with EU commission agreement you get the supreme court (that supersedes all local courts) arguing that anything the commission agrees to can countermand local constitutions.
So local legislature agreement required, in many cases, is incorrect.