Northern Rock is to more than double the number of people who work in its debt management arm, according to a document seen by the BBC.
The internal memo said the recently nationalised bank had the equivalent of 176 full time workers in the division at the end of April. But this number is set to increase to 444 by the end of March next year, the memo reportedly said.
It suggests Northern Rock is expecting to see a big increase in the number of people having trouble paying their mortgage.
In a trading statement issued earlier this month, executive chairman Ron Sandler said the level of mortgages three months and over in arrears was 0.95% at the end of April, up from 0.57% at the end of last year.