We compare the Iwasawa invariants of fine Selmer groups of p-adic Galois representations over admissible p-adic Lie extensions of a number field K to the Iwasawa invariants of ideal class groups along these Lie extensions.More precisely, let K be a number field, let V be a p-adic representation of the absolute Galois group G K of K, and choose a G K -invariant lattice T ⊆ V . We study the fine Selmer groups of A = V /T over suitable p-adic Lie extensions K∞/K, comparing their corank and µ-invariant to the corank and the µ-invariant of the Iwasawa module of ideal class groups in K∞/K.In the second part of the article, we compare the Iwasawa µ-and l 0invariants of the fine Selmer groups of CM modular forms on the one hand and the Iwasawa invariants of ideal class groups on the other hand over trivialising multiple Zp-extensions of K.