An ancient diseased tree in Hampstead has been given a stay of execution after chicks were found nesting in it.

Tree surgeons from Camden Council had already begun scything the black poplar – one of the country’s most endangered native species – on the junction with Lyndhurst Gardens, Belsize Crescent and Akenside Road.

But work was immediately suspended when they found a wood pigeon’s nest in the rotting tree, as it is a criminal offence to disturb nesting birds.

Amateur bird watcher Roger Montgomery, who lives in Belsize Crescent, said: “They should have checked if there were any birds there before starting to cut the tree down. There is hardly anything left of it now.

“It could have been nesting time – I’m not sure whether it is – but that would be the worst time to do it.

“Perhaps if we had known the birds were there it could have saved it. Who knows now?

“It looks like hell now, it was a great tree before and it just looks awful now.”

An arboricultural officer from the council said work to finish felling the black poplar will be postponed until the chicks have fledged and moved on.

Residents have contacted the Royal Society for the Protection of Birds with their concerns for the chicks.

Neighbours have also complained that they have been left with an ugly stump after tree surgeons lopped off most of the poplar’s branches.

Solicitor Liam Naidoo, who was born in Belsize Crescent and still lives there, said: “It’s mind-boggling that experienced tree surgeons would not have checked the tree for wildlife.

“At the moment it’s a bit of an eyesore so we can only hope some foliage will grow back over the spring and summer, if it stays there that long.

“If the council had consulted us on this I would have been able to say there are definitely birds nesting up there.

“It’s an absolutely enormous tree so why would they think that they weren’t nesting up there?”

Extensive tests carried out by arboriculturalists found that 60 per cent of the trunk had rotted.

A council spokesman said the tree will be replaced with a London plane once the chicks have moved on.