Fifty-two innocent people lost their lives in the 7 July attacks

The recordings will be broadcast at a London Assembly review of the emergency services' response to the attacks.

Victims and London Underground staff made calls within minutes of the first explosions that killed 56 people, including the four suicide bombers.

The heads of London's emergency services and Tube bosses will answer questions at City Hall on Thursday.

A London Assembly spokeswoman said: "The first 999 calls will be played at the meeting of the 7 July Review Committee.

It is the human story, their story and one that we do not want to lose London Assembly spokesman

"Some of the recordings will no doubt be quite distressing.

"The committee has been established to examine the response to the attacks, to look at how information was communicated to Londoners and to see what lessons may be learned."

Officials responsible for handling the media at each of the services will be questioned by the five-strong panel of Assembly members.

The London Assembly has asked members of the public for their own memories of the day, which will be included in the document.

The London Assembly spokesman added: "What the public have to say will form part of the historical record. It is the human story, their story and one that we do not want to lose."

It is hoped that the committee can establish if emergency contingency planning worked effectively, how information and communication technology helped the response and if business continuity arrangements were successful.

Further meetings are scheduled to take place on 1 December and 11 January. A report with findings and recommendations for future emergency planning will be published next March.