Felling fig trees necessary evil: minister

Chopping down century-old fig trees is a "necessary evil" to make way for a light rail project through Sydney's east, NSW Transport Minister Andrew Constance says.

A woman was arrested during a heated protest on Anzac Parade at Moore Park overnight over plans to fell the Moreton Bay Fig trees to make way for the rail project.

"We've got to do it, we've got a responsible program to replant the trees and then some, and I'd ask people to be responsible," Mr Constance told reporters in Sydney on Tuesday.

Mr Constance claimed some light rail protesters were engineering a deliberate strategy to "whip up enormous trouble".

"We've copped spikes in trees yesterday, that can kill someone, we've copped nails through ribbons on trees we're not removing, and we've seen trees marked which we're not taking," he said.

"There has been a deliberate misinformation campaign about the trees along and adjoining the road, particularly along Anzac Parade.

"People just need to be responsible; any type of protest action involving spikes, you've really got to question the integrity of what's happening."

A NSW Police spokeswoman confirmed the woman was arrested and later released without charge.

"A 39-year-old woman arrested at the scene of the protest for entering enclosed lands was taken to Maroubra Police Station," the spokeswoman said.

"She was later released pending further investigations."

Her arrest came after hundreds descended on Moore Park at the weekend, calling for a parliamentary inquiry to halt the light rail project to save the trees, as well as ancient Aboriginal artefacts discovered along the route.

Mr Constance on Tuesday argued it was impossible to build the $2.1 billion light rail project without removing some of the fig trees.

"Quite frankly, let's call a spade a spade, we cannot build the infrastructure we're building... without taking trees," he said.

"I don't want to take trees out, but the reality is you've got to. Otherwise, things don't get built, you don't see progress."

CBD co-ordinator general Marg Prendergast defended the trees' removal.

"If we could've redesigned the light rail to avoid those trees we would have but it simply wasn't possible," Ms Prendergast said.

"We have minimised our tree removal and the story that's not being told is the trees we're saving, the trees we're relocating, and the re-vegetation that will start occurring along the alignment."

Up to 760 trees have been slated for removal along a 12-kilometre length of the light rail project, with the state government promising to plant at least two trees for each one removed.