HR jobs are in the firing line following the £1.2bn takeover of RHM by rival food producer Premier Foods.
Last week Premier, whose brands include Branston, Smash and Quorn, announced a deal to swallow up RHM, which produces Mr Kipling cakes, Bisto gravy and other well-known brands.
Premier said it had identified potential cost savings of £85m a year from integrating the two companies. In the offer document, Premier revealed it wanted to "remove duplication in administrative functions and procurement, logistics and manufacturing".
RHM employs more than 15,000 people at 50 locations in the UK and France. A spokesman for Premier said it was too early to say where the axe was likely to fall.
"Premier is very cost disciplined, but is looking to retain as many good people as possible," he said.
Premier has also given assurances that the existing employment rights, including pensions, of all staff will be "fully safeguarded".
Unions have urged the company to show caution before undertaking a cost-cutting programme. The Transport and General Workers Union (T&G), has more than 2,000 production and distribution staff at RHM in its various bakery operations.
Brian Revell, T&G national organiser for food and agriculture, said: "The security of our members' jobs and their pensions at RHM are top of our agenda. We will be urging Premier to meet with us as soon as possible."