I can certainly clarify that. Let me refer you to pages 981 and 982 of the House of Commons Procedure and Practice.
I have it in English here. It states that “certain limitations are recognized on the power to order individuals to appear”.
A little further down, it says:
“This applies...to parliamentarians belonging to other Canadian legislatures, because each of these assemblies, like the House of Commons, has the parliamentary privilege of controlling the attendance of its members and any matters affecting them.”
So the committee can invite Mr. McGuinty, but it does not have the power to compel his appearance.