A record number of officers will be honoured with the highest award for bravery for their work after the 7 July bomb attacks and the Asian Tsunami.
Scotland Yard led the emergency services response to the bombs
At a ceremony on Wednesday, more than 200 will receive Commissioner's Commendations for bravery above and beyond that which is expected.
Of those, 90 will be awarded High Commendations - Scotland Yard's highest award - for showing "supreme courage".
Last year, the Metropolitan Police handed out just four such awards.
For the first time, recipients will also be given a solid silver lapel pin as a visible mark of their contribution.
Commissioner Sir Ian Blair will be joined by London Mayor Ken Livingstone and Len Duvall, chair of the Metropolitan Police Authority to present the awards at the ceremony at the Hendon police training centre in north London.
Lord Triesman from the Foreign Office will help honour those who helped in the wake of the tsunami.
Scotland Yard co-ordinated the emergency services response to last July's attacks when four suicide bombers blew themselves up on three Tube trains and a bus, killing 52 people and injuring hundreds.
In the New Year, 23 men and women from the emergency teams and transport workers who helped victims of the London bombs made the Queen's Honours list.