Both the parliament's left group, The Left, and one of the groups on the far right, PFE, tell the news site Politico Europe that they expect to submit their request after midnight on Thursday.
To bring about a vote, signatures are required from only 72 members – or 144 if it has been less than two months since the last one.
Ursula von der Leyen has recently received increasingly criticism against her, but is still considered to have sufficient support among the members to get by.
