Workers have threatened to strike over fears 80 jobs could be lost at Co Armagh crisp manufacturer Tayto.
The company may also cut production at its Tandragee factory, after it claimed production costs there "are considerably higher than at any of our other sites" in England.
According to Unite the Union, Manderley Food Group - which is directed by Tandragee man Raymond Hutchinson and owns Tayto - had warned it was likely that 80 jobs at its Co Armagh factory would go.
The company said it was not in formal consultation with staff but added there was a "strong possibility" that redundancies at the plant would be considered.
The union says a strike will impact on the supply of supermarket own-brand crisps at Tesco and Sainsbury's, which are made by Tayto.
The news comes as the much-loved local brand celebrates its 60th anniversary, and less than one month after the Manderley Food Group announced after-tax profits of nearly £5m - up from £2.9m a year before.
Over the same period staff numbers at the group also increased from 1,378 to 1,419.
A spokeswoman for the firm said: "Two years ago Tayto Group had an outstanding year, which was reflected in the figures recently published, but this financial year has been more difficult and while things are picking up, business is down. We always experience a seasonal drop in the first few months of the year, but recovery has definitely been slower this year.
"It is only five years ago that the company lost nearly £18m in one year, and while in the last three years we have made a pre-tax profit totalling £17m, we have actually invested more than £18m in capital expenditure. Production costs in Tandragee are considerably higher than at any of our other sites, which are all in England."
The spokeswoman added that only £25m of its £180m turnover comes from Tandragee but added that the company was "extremely proud" of Tayto's Northern Ireland heritage.
She said: "In addition, much of our raw material cannot be sourced locally and has to be brought in from GB and beyond, it is processed at the Co Armagh factory and then 60% of what we produce is shipped back for sale in GB.
"It could be that in the future we will be forced to restrict production here to what is sold in Northern Ireland in order to ensure the continued success of the company and to make best use of our resources, in particular, the capacity we currently have in the more economical Great Britain plants."
Sean McKeever, Unite officer for production and packaging workers at Tayto in Tandragee, said the news was the latest in a series of blows.
He added: "Manderley Food Group appears intent on maximising their profits at Tayto regardless of the cost to the workforce. They have now informed Unite that they will be seeking 80 redundancies in the next few months."
He alleged the company had attempted to avoid paying the newly introduced National Living Wage by counting a monthly bonus payment as part of employees' wages.
On March 22 Tayto had issued a statement saying that it "respected and always will respect the laws of the land". The crisp maker had said "We are complying fully with all legal requirements in respect of the new National Living Wage."
It added that "all colleagues entitled to receive the National Living Wage will receive it".
But Mr McKeever said that workers had been left with "no option but to ballot for strike action". He added: "This is disgraceful behaviour from a group who announced pre-tax profits for 2015 of more than £7m.
"The four directors of this company, including the wealthy Hutchinson family members, were paid more than £1.7m last year in director fees alone and their wealth was estimated in the 2016 Rich List at £67m."