Major plans to transform the 02 Centre into 1,800 homes dominated a hustings for South Hampstead voters.

Residents put Labour and Conservative candidates on the spot about their views on the appropriate height of any development at the site, just off the Finchley Road.

The online event was organised by The Combined Residents Associations of South Hampstead (CRASH), with other parties unable to attend.

Chairman Eric Bergsagel said the council had determined the 950 homes were appropriate for the housing needs.

“Are you prepared to object to more?” he said.

Labour’s Izzy Lenga said they were “arbitrary numbers” and felt she could not give specifics, but said “our focus is on affordable housing and making sure that the people on the housing register are getting the right safe housing”.

She pledged to work with residents. The current scheme includes 35 per cent affordable homes.

Nina De Ayala Parker, for Labour, said 14 storeys was too high: “We are concerned about the height. We need affordable housing but not at the risk of a very tall building. We want to push back.”

She was asked what she thought was suitable and responded: “I think 10 storeys is a manageable height.”

Conservative candidate Marx de Morais said he wants to give residents a strong voice against the proposed development.

He said: “Together we will stop this concrete disaster.”

He criticised the Labour ruling party on last term’s council for not backing a Conservative proposal to outlaw inappropriate high rises.

He said: “This time [the election] is about a building site. It is a referendum about the 02.”

Conservative Calvin Po, who trained as an architect but is now working to tackle climate change, said: “Demolishing a 19-year-old building is a huge contribution to carbon emissions. We need to retain the structure.”

Residents also raised concerns about the loss of mature trees in private gardens – with an estimated 60 felled in the last seven months.

Both parties pledged to tackle this issue.

Labour pledged to plant 2,500 trees by 2026 and open a New Opportunity Centre for children to study. Other pledges include more CCTV and electric vehicle chargers.

Conservative promises include standing up to developers, campaigning against unsuitable high rises, and tackling the climate crisis, with 1,000 electric vehicle chargers and tree-planting.