The Courts have a degree of control over legislation approved by the Parliament, in interpreting the law and, as to the Constitutional Court, in determining whether the law is consistent with the new constitution. Any law found to be inconsistent with the Constitution by the Constitutional Court is rendered ineffective, and cannot be followed. The Courts also review governmental actions, and can require changes or reconsideration in appropriate cases, such as environmental reviews.
The Executive Branch, through the power of preparing the budget, has a degree of control over the functions of the courts, and how many employees the courts may have, etc. The legislative branch also has a direct say in the budget process. The executive branch also has control over legislation passed by the Parliament, in that all bills must be submitted to the King through the Prime Minister, and if the Prime Minister is opposed to a particular bill, he can express those feelings to the King, who may refuse to approve it in the form in which it is submitted to him.
The power of each separate branch of government to in some way or other affect the others' actions is known as the system of "checks and balances." Each branch has at least some authority to place limits upon the actions of the other.