You are in duty bound to call their bourgeois-democratic and parliamentary prejudices what they are—prejudices. But at the same time you must soberly follow the actual state of the class-consciousness and preparedness of the entire class (not only of its communist vanguard), and of all the working people (not only of their advanced elements).
We're still in the pretty heavy wake of McCarthyism, we're not at "run our own candidates on the general ballot" yet, we're at "vote lesser evil on the general ballot while we run our own candidates locally and try to win primaries".
Whilst you lack the strength to do away with bourgeois parliaments and every other type of reactionary institution, you must work within them because it is there that you will still find workers who are duped by the priests and stultified by the conditions of rural life; otherwise you risk turning into nothing but windbags.