Cereal firm Weetabix has placed between 50 and 60 jobs in its industrial hygiene department at risk across both its Burton Latimer and Corby sites.
The firm said an external firm was being brought in to carry out industrial cleaning at the sites from the autumn.
As a result, consultations are being held with dozens of workers at the two plants.
A spokesman for Weetabix said: “Following a tender process it is our intention to appoint an external specialist cleaning company this autumn.
“Weetabix has a strong working relationship with all of its trade unions and our colleagues at our Burton Latimer and Corby sites, and we are currently consulting with employees affected by this.”
A Weetabix employee, who asked to remain anonymous, contacted the Telegraph last Thursday, the same day the announcement was made.
He said: “We were told in January that the jobs were going to be reviewed.
“People came in to look at the department and then last week we were told that the work of the whole team, about 50 to 60 people in all, was all being completely outsourced in a few months time.”
Weetabix employs about 2,000 people across its two sites in Corby and Burton Latimer.
A spokesman for USDAW said the union was speaking to bosses at Weetabix.
He added: “Following the announcement last Thursday, USDAW representatives will be entering into a full and meaningful Transfer of Undertakings (TUPE) consultation process with Weetabix, as a consequence of their decision to outsource the Industrial Hygiene Specialist Department.”
Earlier this year, the Telegraph reported that Weetabix was consulting staff over new shift patterns and associated payments – in a bid to cut costs.
At the time Weetabix said its profit margins were being eroded, adding: “We are seeing a continued decline in the cereal market through the main supermarkets.
“This decline is more significant than we anticipated.
“Volume can be sold through the discounters, however they expect significantly lower cost products therefore eroding margin.”
Weetabix was family owned until 2004 when it was sold off.