Brothers and Sisters, it is allowed that someone will serve the Catholic Church and Government at the same time (except by priests, nuns, and religious) as long as he/she will do the tasks with love (1 Cor 16:14), keep the commandments of Christ (Jn 14:15), and will do the responsibilities as a government official (Rom 13:1-6).
Example of this situation was Joseph of Arimathea and he was a COUNSELOR AND ACTIVE IN JUDAISM (Lk 23:50-51).
Other example is Bro. Socrates Fernandez, a Catholic Faith defender and Government official in Talisay City, Cebu.
We have to remember also that the Church and State have different functions at all and there’s separation between church and state.
In short, a person will separate his/her responsibilities as government official and as servant of the church.