A Hollywood couple is backing a campaign by schoolchildren to block plans for a luxury home next to their playground – which they claim would blight the Belsize Park school forever.

Ham & High: St Christopher's School Parents & children protesting against plans for a housing development on the edge of their school.St Christopher's School Parents & children protesting against plans for a housing development on the edge of their school. (Image: © Nigel Sutton email pictures@nigelsuttonphotography.com)

Actors Damian Lewis, from TV’s Homeland, and wife Helen McCrory, who starred as Narcissa Malfoy in the Harry Potter film series, joined hundreds of pupils from St Christopher’s School – including their daughter – to protest against plans for a neighbouring modern three-bedroom house.

Leisure complex

If the plans go-ahead, construction vehicles will descend on the site in Lyndhurst Gardens to dig out a two-storey basement leisure complex.

The all-girls primary school, which charges almost £4,000 a term, said the new house would tower over its playground and dust from the construction work would prevent them using their science garden.

The thespian couple, who sat opposite President Obama at a White House dinner last year, joined around 30 parents at a planning hearing on Tuesday to object to the plans.

Ms McCrory, who played Cherie Blair in Oscar-winning film The Queen, told the Ham&High: “It’s amazing. You have hundreds of people complaining because someone wants to build a swimming pool.”

Dozens of school girls marched on Camden Town Hall last September armed with placards bearing the campaign slogan “education not excavation”.

They helped convince planning officials to reject the plans to bulldoze a 1970s two-bedroom bungalow and replace it with the luxury home, featuring a swimming pool, gym and sunken courtyard.

But developer Lyndhurst Gardens LLP, set up by company Vabel, is now challenging the decision through the Planning Inspectorate.

Representing the school at the hearing was QC Fiona Parkin, of Wedderburn Road in Belsize Park, who has a daughter at the school.

She said: “The wall (of the home) is going to be raised and the building will stand up above the school.”

Headmistress Susie West said: “For us, plonking down this mass of brick will create a sense of enclosure for the pupils.”

Stephen Brown, of Croftdown Road, Dartmouth Park, who has two daughters at the school, said: “The serenity and enjoyment the girls have from the place will be impacted quite severely.

‘‘You have to balance the interest of many generations of school girls against one home owner.”

Stephen Gray, a heritage consultant employed by Vabel, said: “The area is a choir singing a rather rousing piece of Edwardian music by Elgar and the existing bungalow is singing rather out of key, but quietly, so no one really notices.”

He added that the new house would be a “descant singing against the prevailing tune, which can be a beautiful thing”.

A decision on the planning appeal will be made in coming weeks.