Your passport is not damaged.
These are not oil marks or any other form of damage, they are an element of the passport design itself. The same pattern can be seen in the example passport data page below (taken from p.5 of this Passport Office document, published when this passport design was introduced).
They are presumably a security feature, although the exact nature isn’t mentioned anywhere within the document.
Credit:stackoverflow.com‘
5 Mar, 2024
4 Mar, 2024
5 Mar, 2024
5 Mar, 2024
4 Mar, 2024