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Shiba impurities are appealing because of the exotic phenomena they exhibit. Their study has also implications for the quest of nonabelian Majorana quasiparticles, the building-block of fault-tolerant topological quantum computation proposals. It is also relevant in the context of the 0-π phase transition in quantum dots. Here we analyze the effect of reduced dimensionality of the superconductor and correlations on the properties of the transition by means of bosonization. We find that the ground state properties of the system become related to topological soliton solutions of the classical equations of motion of the bosonic fields. Contrary to the three dimensional case, where the spherical symmetry together with the existence of stringent boundary conditions on the effective one dimensional radial coordinate allow for a only a single subgap state, two states emerge, whose degeneracy is controlled by interactions. In the degenerate regime we predict a novel ''0-0 transition'' in which the parity of the ground state is preserved.