Prime Minister Justin Trudeau is to testify Thursday afternoon about his government's decision to get the WE organization to run a summer student-volunteer program.
His chief of staff Katie Telford is to follow him for questioning by the House of Commons finance committee.
WE backed out of the program in early July, citing the controversy over the Liberals' handing the organization a sole-sourced deal despite its ties to Trudeau and Finance Minister Bill Morneau.
Several members of Trudeau's family have been paid hundreds of thousands of dollars between them for appearances at WE events, most notably his mother Margaret.
And Morneau, whose daughter works for the organization, admitted last week to having not repaid more than $41,000 in travel expenses for visiting WE projects, saying it was an accidental oversight.
The opposition Conservatives and Bloc Quebecois have called on both to resign.