The opposition at city hall is calling it a chainsaw massacre.

A plan to chop down 1,000 trees to make way for a new amphitheatre in Jean-Drapeau Park is being harshly criticized.

The huge year-round amphitheatre would seat 65,000 people for events such as the Osheaga music festival.

The number of trees to be cut down wasn't made clear until Thursday.

Projet Montreal said it shows how poorly planned the $73-million project to revamp Jean-Drapeau Park is.

Announced in 2015, the project won't be ready this year for the city's 375th anniversary as originally planned, but rather for next year.

Projet Montreal said the city should have looked into better, greener examples of amphitheatres

“If you look around in other countries and in other places they've done amazing types of infrastructure that doesn't destroy the whole environment around. This is what's happening right now and again this is going to benefit only a few private promoters. What about Montrealers? What about people that are going in the park to enjoy nature to enjoy the trees,” said Projet Montreal leader Valerie Plante.

Mayor Denis Coderre said the city has been consulting heritage officials on the project since 2015 and believes it's time to polish the gem that is Jean-Drapeau Park by making the site more than a muddy field for huge concerts.

Coderre also said the city is investing $18 million in planting new trees.