Semi-Pelagianism was condemned in 529 at the Council of Orange. Catholics are not in any way Pelegian.
If a Protestant states that Catholic teaching is semi-Pelagian then they must also confess that their teaching of salvation by faith alone is also semi-Pelagian. Faith and works are both by grace. If one argues that works are Pelagian then they must also argue that faith is Pelagian.
Furthermore, scripture even says that faith is a work. The following passages should make this clear:
In John’s vision in the book of Revelation, Jesus warns members of the church at Ephesus that they might be destroyed if they do not repent and return to the love they once had. This is very clear in Rev 2:4-5 where Jesus says, “But I have this against you, that you have abandoned the love you had at first. Remember then from what you have fallen, repent and do the **works **you did at first. If not, I will come to you and remove your lampstand from its place, unless you repent.” Then again just before addressing the transgressions of the church at Thyatira, Jesus says in Rev 2:19 that, "I know your works, your love and faith and service and patient endurance, and that your latter works exceed the first.” These verses are significant in two ways. They show the necessity of love in the plan of salvation, and they show that both love and faith are referred to as works.
Paul also makes this point in 1 Thessalonians 1-4
PAUL, SILVANUS, and Timothy, To the church of the Thessalonians in God the Father and the Lord Jesus Christ: Grace to you and peace. We give thanks to God always for you all, constantly mentioning you in our prayers, remembering before our God and Father **your work of faith **and labor of love and steadfastness of hope in our Lord Jesus Christ. For we know, brethren beloved by God, that he has chosen you;