On May 27, 2003, the Liberal government of Jean Chrétien attempted to decriminalize cannabis use by introducing a bill that would make possession of 15 grams or less punishable only with a fine. The bill looked likely to pass into law, but it died when Parliament shut down. The bill's death was largely due to pressure from the American government's Drug Enforcement Administration, which had threatened to slow down border-crossings along the border, with increased searches for cannabis.

An identical bill was introduced in November 2004 by the Liberal government with Paul Martin at the helm. Martin's government was defeated in a confidence vote, so this bill never passed. After the Conservative victory in 2006, the new government did not continue with this legislation.

It wasn't until Justin Trudeau's victory as leader of the Liberal Party of Canada in the 2015 election that decriminalization of cannabis began to gain traction again.