What’s behind Mars UK’s £190M investment in its historic confectionery hub?
Over the past decade, UK manufacturing has faced persistent headwinds, from Brexit to Covid and ongoing supply chain disruption. Yet manufacturing still accounts for almost 9 per cent of UK GDP.
Set against this backdrop, a major new investment from a global company at its historic Slough factory signals a vote of confidence in UK manufacturing.
The company in question is Mars, Incorporated which is investing £190 million to transform its flagship Slough factory into a next-generation manufacturing hub – a move that signals both a bet on UK production and a modernisation of one of its most historic sites.
Established by Forrest Mars in 1932, the Slough factory is the birthplace of the iconic Mars bar, and is now home to many of the company’s best-known brands including Galaxy, Maltesers and Snickers. As well as supplying the UK, the site also produces chocolate for Ireland and the Netherlands.
The investment – which will be rolled out between 2023 and 2028 – marks the largest ever commitment to the site. Forming part of a broader push by Mars to futureproof its manufacturing footprint at its historic location, the upgrades focus on sustainability, advanced technology and upskilling the Associates working there.
Modernising a legacy site
At the core of the upgrade is a significant overhaul of factory technology. Mars has introduced a combination of robotics, artificial intelligence, and advanced data systems to improve efficiency and consistency across production.
Amongst the most notable developments is the rollout of new digital twin technology, which enables precise process control, consistency and real-time optimisation. The aim is to ensure greater uniformity across product lines – delivering consistency (essentially the “perfect Mars Bar”) for consumers across multiple markets.
The site will also see improvements to cooling systems and utilities designed to reduce energy use and waste – supporting the company’s wider net zero ambitions, which includes transitioning to 100 per cent renewable energy and reducing emissions across its supply chain and logistics networks.
A vote of confidence in UK manufacturing
The latest commitment builds on over £118 million in UK capital investment across the company’s snacking, food and pet care businesses – its portfolio also includes M&M’S, Ben’s Original, Extra, Pedigree and Whiskas among others – in 2024 to 2025. This is a signal that it is not simply a one-off investment, but rather a sustained contribution to the UK economy, to support British manufacturing and strengthen the country’s position as a hub for production and innovation.
Business and Trade Secretary Peter Kyle said the investment underscores the UK’s appeal to global manufacturers.
“This £190 million investment by Mars is a strong vote of confidence in the UK as a place to manufacture and innovate. For nearly a century, the Slough factory has produced some of the world’s best-loved brands, and this investment shows global businesses continuing to back British skills, workers and industry,” said Business and Trade Secretary Peter Kyle.
A workforce fit for the future
The family-owned business isn’t just focusing on upgrades on the factory floor, it is also investing in its 1,850 strong workforce.
As a commitment to its Associates – and equipping them with everything they need to succeed as manufacturing evolves – the investment will support workforce upskilling, leading to the creation of new routes into engineering, automation, data and manufacturing roles.
Beyond the factory gates, Mars UK continues to emphasise its role in the community – through community volunteering, litter clean-ups, and food bank support. Mars Associates also work closely with local schools, offering mentoring and apprenticeship guidance, driving greater diversity, with 77 per cent now coming from low socio-economic or ethnically diverse backgrounds.
A new chapter for a historic site
“This investment reflects our confidence in the UK as a hub to manufacture and innovate,” said Adam Grant, general manager at Mars Snacking UKI.
In taking a long-term view, we are ensuring our operations remain world-class, competitive and fit for the future.
“Our Slough factory is deeply rooted in our heritage, and as a proud family-owned business, we are committed to investing in a future that creates lasting, positive impact for the communities in which we operate,” he added.
Nearly a century on from its founding, the factory is entering a new chapter – one defined as much by innovation and automation as by its heritage – positioning both the site and the wider sector for sustained growth in the decades ahead.