Hundreds of protesters took to the streets of French-speaking Montreal and Quebec City on Sunday in support of gay marriage and adoption in parallel with a mass demonstration in Paris.

The protest in front of the French Consulate in Montreal saw more than 300 people turn out, with activists hoisting rainbow flags and banners alongside leftist supporters.

Earlier, tens of thousands of gay rights campaigners packed the streets of Paris to call for the legalization of gay marriage and adoption two days before a key parliamentary debate on the hugely divisive issue.

Brigitte Sauvage, a leftist member of the Assembly of French Citizens Abroad, expressed hope that the French bill would "end the drama and problems that can not last much longer."

The proposed legislation, which has encountered strong objections from the mainstream center-right opposition, the Catholic church and France's five-million-strong Muslim community, is due to be debated in parliament on Tuesday.

The bill stems from a promise by President Francois Hollande in his election manifesto last year.

In Quebec, young protesters waved banners, some of them humorous, in support of the legislation.

"Better have a gay marriage than a sad wedding," read one.