Róża Thun and Ryszard Czarnecki are both expected to appear before Antonio Tajani this week.
Thun has threatened legal action against Czarnecki over remarks he is alleged to have made in an interview.
Czarnecki apparently likened Thun to a “szmalcownik” a derogatory term denoting people who blackmailed Jews hiding from the Nazis or informed on them to the occupying forces under German occupation in Poland during World War II.
In a radio interview, he is alleged to have said, “During World War II we had ‘szmalcownicy’, nowadays we have Róża von Thun.”
The broadcast led to demands from political group leaders for Czarnecki to be stripped of his vice presidency role in Parliament.
The MEPs said that Czarnecki’s “remarks exceed the boundaries of responsible political discourse, both on a personal and institutional level.”
The Conference of Presidents met in Brussels last Thursday and discussed the furore.
On Monday, a Parliament spokesperson said Tajani “was asked to speak to Czarnecki and Thun and report back at the following Conference of Presidents.”
Czarnecki’s reported comments - for which he has refused to apologise - came after Thun appeared in a documentary by German state NDR Television talking about the current political situation in Poland.
She said that under the ruling party, Poland was turning away from the European Union and was veering toward a dictatorship.