The family intend to read the message out at the vigil and said they were "pleased the Mayor has sent supportive words at this difficult time".
The Mayor's message reads:
"As Mayor of London, I'm sure I speak for all fellow Londoners when I send my sincere condolences to the friends and family of Ian Tomlinson.
Christmas is a time for families but for members of the Tomlinson family this will be a very difficult Christmas without their loved one.
Our thoughts are with them."