News International chief executive Rebekah Brooks is likely to face new calls for her resignation today.
It follows more revelations about the apparent scale of phone hacking at the News of the World.
It has been reported families of victims of the 2005 London bombings have been told they may have been targeted.
The parents of murdered schoolgirls Holly Wells and Jessica Chapman have also been contacted by officers on the hacking inquiry.
British MPs will consider whether there should be a public inquiry into the saga, when they hold an emergency session later today.
Assistant Editor and Media Editor at the London Independent Ian Burrell said the pressure "is mounting" on Ms Brooks.