Brazil Prosecutors Plotted Against Lula's Party in 2018

The alledged political motivations of the prossecutors is very much irrelevant as

a) Lula was in fact guilty of operating an extensive criminal organization that transcended his party (in fact the interim president was also caught and is currently jailed)

b) Lula and his minions quite overtly stated that if they were elected they would abuse political immunity to avoid payung for their crimes and also abuse presidential pardons left and right to ensure every single member of their criminal organization would pay for theie crimes.

Therefore any concern with Lula and his minions winning the election has more to do with not wanting the criminals they were prossecuting to get off due to political trickery.