Anthony Housefather said Thursday that Bill 14 could be harmful because a community's status would depend on the latest census data, and would be up for review every ten years. It would remain bilingual only if English is the mother tongue of a majority of its population.
The status of cities like Westmount, Hampstead and Côte-Saint-Luc would be questioned.
According to Housefather, nearly 85 per cent of people in Côte-Saint-Luc use English as their preferred language.
He said anglophone communities should join forces to fight the amendments made to Bill 101.
"We've had bilingual status since 1977. Who in Quebec has been impacted by Côte-Saint-Luc having bilingual status? Is anybody in Jonquière affected? Is anybody in Quebec City affected? So why change that? Why does the PQ want to attack us?" said Housefather.
Marois, on the other hand, said the new bill is not meant to deter anglophones or allophones from speaking their own language, but is used as a measure for boosting French.
"The anglo Quebecers are not losing anything," said Marois. "Au contraire, I think we recognize their rights to have access to their services in health, in municipal services and any other service in their language."
The new legislation was introduced by the PQ on Wednesday and would add new restrictions on the use of English in the workplace.
The amendments brought to the province's language charter, often referred to as Bill 101, also propose changes to the province's Charter of Human Rights and Freedoms.
Among the proposals, Bill 14 is widening its scope and will oblige businesses with as few as 26 employees to comply with the rules set out in the French Language Charter.