The constitutional lawyer who torpedoed Stephen Harper's pick for the Supreme Court says he will contest the government's anti-terror legislation in court, if it passes.
His speech contained some incendiary allusions to Nazi Germany.
Appearing next to NDP MP Andrew Cash, Galati said C-51 creates "a modern-day Gestapo," referencing the brutal, secret Nazi police force.
"No exaggeration, that's what it creates," he said. "It chills, censors, and criminalizes free speech, free association, and constitutional rights of assembly."
Galati added that "German and Italian versions" of C-51 were passed in the 1930s.
The lawyer received big applause when he urged Canadians not to vote for any MP or political party supporting the controversial Tory bill. The Liberals voted in favour of its passing, but have vowed to amend the legislation if they win the next election to provide better oversight of national security agencies.
New Democrat and Green MPs voted against the bill.
"This is quite clearly a fascist and dictatorial piece of legislation and appeasement of it is unacceptable," he said.
Galati vowed that his group, the Constitutional Rights Centre, will fight the bill in court.
Several hundred protesters gathered at Queen's Park Saturday to call on the Senate to stop the bill, the Toronto Sun reports. Though some Liberal senators have said they will vote against C-51, it is expected to easily clear the upper chamber.
The bill has been denounced by the federal privacy commissioner, the Canadian Bar Association, First Nations groups, environmental organizations, and civil libertarians. Tories, however, have countered that the measures in the bill are needed to keep Canadians safe.
C-51 gives the Canadian Security Intelligence Service enhanced power to actively thwart terror plots, broadens no-fly list powers, and increases the exchange of federal security information. It also creates a new criminal offence of the act of encouraging someone to carry out an attack.
The bill also makes it easier for the RCMP to obtain a peace bond to restrict the movements of suspects and extend the amount of time they can be kept in preventative detention.
C-51 passed third reading in the House of Commons last month by a vote of 183 to 96.
With files from The Canadian Press