MPs passed the Liberal government's bill to legalize cannabis Monday evening, sending the legislation down the hall to the Senate for further study and debate.

The legislation was largely supported along partisan lines, although it secured the support of the NDP and Green Party Leader Elizabeth May. The final vote was 200 MPs in favour, with 82 against. Conservative MP Scott Reid voted for the bill after he polled constituents in his eastern Ontario riding, Lanark—Frontenac—Kingston, and found a plurality supported the Liberal plan.

A last-ditch Conservative effort to delay the bill — and send it to the Commons health committee for further study — failed by a vote of 83 to 199 with some Bloc Québecois MPs voting with Tory legislators. Conservative opposition will now fall to their national caucus colleagues in the Red Chamber, where some senators have already signalled they are prepared to give the bill a rough ride. Some Tories have said the government's timeline for legalization, July 1, 2018, is far too ambitious.

The Liberal government ultimately accepted three significant amendments to the bill made by the Commons committee tasked with studying the landmark legislation — the government has agreed to ditch its plan to cap marijuana plants maintained in a person's home to 100 centimetres tall. MPs felt such a requirement would be too difficult to enforce. The government also accepted an amendment that would demand regulations be enacted, one year from Bill C-45's passage, on edible cannabis products, something ignored by Liberal legislators in this bill.

The government also agreed to review the bill in three years.

The bill will have to secure the support of an increasingly independent Senate where a plurality of members now sit as members of the Independent Senators Group (ISG) and thus owe no loyalty to the government's agenda or their Liberal colleagues in the House. However, based on a CBC News analysis of voting patterns, many ISG senators have shown to be faithful backers of Liberal legislation.

Justice Minister Jody Wilson-Raybould had said, before the vote, that Bill C-45 marks an "important milestone" in the government's plans to keep pot profits out of the hands of organized crime and marijuana out of the hands of kids.

She also says she looks forward to further debate in the Senate.

The federal NDP supported the government's legislation, adding it was pleased to see amendments to the bill, including a decision to scrap a requirement that limited home-grown marijuana plants.

New Democrat health critic Don Davies said the original bill was also amended to require that legislation for cannabis edibles and concentrates be brought forward within a year.

Conservative health critic Marilyn Gladu says the Tories have been pushing for the Liberal government to reconsider its arbitrary timeline for implementing marijuana legalization, noting it would be more responsible to consider a July 2019 deadline instead of July 2018.