The NUJ has described ITN's plans to slash almost half of staff working on ITV London Tonight as 'savage".
The broadcaster announced that 15 or the 36 staff working on the 6pm bulletin are at risk of redundancy.
The restructuring will reportedly see the programme integrate with ITV's national news centre, which will include sharing journalists and office space.
According to The Guardian, ITV News editor Deborah Turness told staff: "As a news supplier it is incumbent upon us to review the way we make our programmes, and to seek more flexible and efficient ways to operate.
"These changes will see our London news service maximise the benefits of the team's proximity to the national news operation, including a move to the network news studio which will deliver a larger, HD home for our regional programmes.
"Our plans will ensure a more co-operative approach to newsgathering and production and a more sustainable future for ITV London news."
NUJ broadcasting national organiser Sue Harris issued a statement saying: 'These are savage cuts and are bound to have an impact on the quality of London Tonight's service. The management has said it will be looking for voluntary redundancies and we will be working to support our members against compulsory job losses.
'The NUJ hopes to continue to have constructive talks with the management. We are also concerned that those who are left will be put under stress, with unreasonable workloads, as they attempt to cover for the lost posts."