The treaty basis of the Gibraltar dispute

What is Spain's legal case for Gibraltar if the Treaty of Utrecht is clear?

The claim is largely political pressure to reverse the treaty rather than a stronger reading of the treaty itself.

The Treaty of Utrecht is clear in this reading about Gibraltar's transfer to Britain. Spain's modern position becomes an attempt to reverse the settlement instead of a stronger textual claim. Spain's own role in starting the war also weakens the argument that the treaty was imposed after fighting. Condemning enclaves while retaining Spanish territories on the North African coast creates a further inconsistency.