Up to 900 jobs will be cut across Nationwide and Portman after the two building societies merge later this summer, it was disclosed today.
Nationwide chief executive Graham Beale said the 500 staff cuts already announced in March were set to almost double within two years as the group looks to trim jobs in the combined business.
About 250 jobs are set to go in Portman's Bournemouth head office, which will instead become an administration centre, with another 250 due to be axed when Portman's Wolverhampton base is closed at the end of the year.
But Mr Beale said Nationwide now expected a further 100 jobs to be shed within the combined retail network, "at a management level", with another 200 to 300 cuts, largely expected to be within Nationwide's sub-prime lending arm UCB Home Loans.
Nationwide announced earlier this week that UCB would relocate from Sutton to Bournemouth to be based alongside Portman's specialist lender The Mortgage Works.
The group said it would "make every effort to transfer the skills, knowledge and experience of its employees and encourage them to seek alternative opportunities within the organisation wherever appropriate", although today's higher figure for job losses suggest some of UCB's 330 jobs may go.
Nationwide pledged in March that there would be no compulsory redundancies among Portman's branch counter and sales consultants teams within three years of the merger.
However, about 88 Portman branches are to be closed or merged with Nationwide branches in areas where both societies have a presence.
The combined group will have a network of 894 branches. Assuming 900 jobs, the enlarged Nationwide group will be left with about 17,600 positions.