Capping an extraordinary exchange of demands and counter-demands, a lawyer for WE Charity's co-founders agreed late Thursday that Craig and Marc Kielburger will appear Monday before the House of Commons ethics committee.

As long as he can "intervene where necessary to provide advice to our clients," lawyer William McDowell wrote in a letter to the committee's chair, Conservative MP Chris Warkentin.

"As you can appreciate, counsel must be permitted to protect clients’ rights in this way rather than to be relegated to a purely ornamental role," he wrote.

The brothers' appearance has been in doubt after a fresh spat broke out between the Kielburgers and the MPs who want to grill them about the organization they founded.

The brothers suggested they might not accept a summons to appear at the committee Monday unless a list of conditions were met.

Those demands came after the pair first accepted the summons issued unanimously by committee members earlier this week, which followed the Kielburgers' initial refusal to testify in response to a gentler invitation.

In a letter the day before, McDowell wrote that police could draw on information gleaned in the meeting, even though it falls under parliamentary privilege.

"While it may be true, in a limited sense, that 'Parliamentary privilege ensures that anything said in Parliament cannot be used in any other proceeding,' you will appreciate that law enforcement agencies and others are free to use the information disclosed in committee hearings," McDowell wrote to Warkentin in a letter posted by a WE Charity Twitter account Wednesday evening.

NDP ethics critic Charlie Angus has asked the RCMP and the Canada Revenue Agency to investigate the Toronto-based organization's operations.

Kielburgers will appear before Commons committee on Monday: lawyer #CDNPoli #WECharity

McDowell demanded that WE's lawyers be able to appear on camera in the virtual hearing, make an opening statement and intervene to object to questions put to the Kielburgers during testimony.

The ethics committee had already agreed to the brothers' request that their lawyers be present and to push back the hearing to Monday from Friday to give them more prep time.

"To be clear, it is not my intention to provide substantive answers to the questions, but rather to intervene as necessary to protect our clients' rights," McDowell's earlier letter said.

"I'm not really sure what's behind these theatrics from the Kielburger brothers," Angus said in an interview before their conditional promise to appear landed Thursday evening. "The issue is, there is an outstanding legal summons compelling them to testify. That's an extraordinary step that we've had to take in order to get answers."

"There's almost no precedent in the history of Parliament for someone refusing a legal summons … and the heads of a Canadian charity doing that would be certainly dramatic."

In that situation, the case could go to the House of Commons, which could order witnesses to appear. Witnesses who still refuse could be declared guilty of contempt.

"My advice to them is just calm down, take a deep breath, show up and answer the questions and do the right thing," Angus said.

Both the Commons ethics committee and its procedure and House affairs committee have invited the Kielburger brothers to testify as part of their ongoing scrutiny of a federal agreement to have WE manage a now-cancelled student services grant program, despite the organization's close ties to Prime Minister Justin Trudeau and his family.

Ethics commissioner Mario Dion is investigating the involvement of Trudeau and former finance minister Bill Morneau, who also has family ties to WE, in choosing the organization for the task. Both have apologized for not recusing themselves from the decision.

The RCMP declined to confirm whether a probe is underway.

"The RCMP continues to examine this matter carefully with all available information and will take appropriate actions as required," the police force said in an email.

Guy Giorno, a legal adviser to WE and once chief of staff to Conservative prime minister Stephen Harper, questioned the notion that parliamentary committees are the appropriate forum for investigating private organizations.

"These things were never actually meant to be used in some kind of a political skirmish with people outside government," he said in an interview.

“People alleged to have done things are answerable to the law and the legal process and due process, not a bunch of partisan politicians."

Giorno said the Kielburgers had been willing to appear before the ethics committee until Angus tweeted on Feb. 28 that he had written to the national revenue minister, who oversees the Canada Revenue Agency, as well as the RCMP to request an investigation regarding WE's fundraising practices.

"That changed the stakes for the organization incredibly, because of the risk," Giorno said. "They could be caught by having proceedings."

Angus noted that Conservative MP Michael Barrett asked RCMP Commissioner Brenda Lucki in a letter dated July 10 to investigate alleged wrongdoing over the federal contract initially awarded to WE. The Kielburgers testified at committee later that month.

"These are long-standing parliamentary conventions protected by the Constitution going back 170 years: the right to draw witnesses, the right to compel testimony, and the right of parliamentarians to ask questions," Angus said. "It's pretty straightforward."

This report by The Canadian Press was first published March 11, 2021.