The Constitutional Court (in Latvian Satversmes tiesa) is an independent court which reviews the lawfulness of different laws and regulations in Latvia. It works on the basis of the Constitutional Court Law.
The Court may declare laws or regulations invalid if it determines that they conflict with a higher law or the Constitution of Latvia. You can only apply to the Constitutional Court if you believe that a certain law violates those human rights which are laid out in the Constitution of Latvia.
Only the Court and the institution who adopted the law or regulations and can annul them. The Court can also choose the date from which a law has lost its force. For example, the Court may declare that the law you are complaining about was invalid all along and its application in your case violated your human rights. Or, it can decide that the law will no longer be in force from the day of the judgement, but it was valid and in force when it was applied to you.
The decisions and judgements of the Constitutional Court are binding and they cannot be appealed.