I agree with Firefly.
From FA's link:
http://www.mapleleafweb.com/features...structure.html
"The Senate can amend, delay, or refuse to pass bills introduced in the lower House."
"Under the 1982 Constitution Act, the House of Commons has an absolute veto
over constitutional amendments, while the Senate has a 180 day suspensive veto. This means the Senate can only delay the legislation for 180 days. " (emphasis mine)