Trade Union Amicus said members have been left devastated by the announcement of the loss of 750 jobs at Norwich Union.
The union said it would begin meetings with senior management this week to start consultation on the proposed job cuts.
Amicus said it would oppose the compulsory redundancies and will argue that redeployment and retraining of staff to fill existing vacancies would be the best approach for the insurer to take.
The union also said it would be seeking further information on what percentage of the jobs will be offshored or outsourced to UK IT and business services companies.
Amicus national secretary Dave Fleming, said: “This is devastating news for Norwich Union staff within its Life IT & Project Management area, especially after last years massive offshoring announcement that affected nearly 2,500 staff.
“The 700 job cuts announced this morning amount the 50% of the total employed within this area. We will be meeting with Norwich Union management to get a full picture of their business case for these cuts.
“However, we will vigorously oppose any compulsory redundancies and any offshoring of these jobs abroad.
