Canadians voted for Jack Layton, but "Jack Layton is dead." said Quebec MP Lise St-Denis at a press conference this week. Her decision to leave the NDP and join the Liberal ranks raised a lot of questions about the impact and implications that come when MPs cross the floor. Here to answers those questions is Kady O'Malley:

If you have a question about the inner workings of Parliament Hill send Kady an email at thehouse@cbc.ca.