Telecommunications company Vodafone is cutting between 200 and 250 jobs by March next year.
The announcement has taken the union representing staff by surprise, as it is preparing feedback to the company about proposed job cuts.
Engineering, Printing and Manufacturing Union (EPMU) spokesperson Joe Gallagher said consultation from Vodafone had been shoddy.
Listen to Joe Gallagher
The EPMU was first informed about jobs being slashed through the media, then officially notified last week and given a deadline for feedback by the end of that week, he said. The deadline for consultation was then moved to today.
"We think it's a lack of consultation and an extremely short timeframe for our members to be able to consider the proposals. We believe that it's been treated as a done deal."
Every discussion with Vodafone was a debate, Mr Gallagher said.
A spokesperson for Vodafone said teams were still in consultation and they had not assessed the impact for staff who were EPMU members.