1. Is there a ban on donations from foreign interests to political parties?

Political Organizations Law: article 31, c and e                                                      

"Artículo 31º.- Fuentes de financiamiento prohibidas
Las organizaciones políticas no pueden recibir aportes de ningún tipo provenientes de: (...)
c) Personas jurídicas con fines de lucro, nacionales o extranjeras.
e) Personas naturales o jurídicas extranjeras sin fines de lucro, excepto cuando los aportes estén exclusivamente destinados a la formación, capacitación e investigación".                                                                                                                                

"Article 31.- Banned sources of funding                                                                    

Political organizations cannot receive contributions of any type with origin of: (...)   

c ) Legal persons with lucrative purposes, national or foreign.                       

e) Natural or legal persons  with non lucrative purposes, except when contributions are destined toward training and research.

This ban is applicable since 2017: Law 30689 modified Political Organizations Law.                                                                                                                                   

Reglamento de Financiamiento y Supervisión de Fondos Partidarios (aprobado por Resolución Jefatural N° 001669-2021-JN/ONPE): article 65.

Legal persons with lucrative purposes (including foreign ones) are banned on donations. Foreign people and foreign legal persons with non lucrative purposes are also banned, with the exception of contributions towards training and research.