The remembrance service at the Cenotaph will be shortened to limit standing time for the Queen and ageing veterans.
The changes will see the leaders of the opposition parties and some members of the Royal Family lay their wreaths together rather than individually.
The shortened format follows discussions with the Royal Household but raised eyebrows at Westminster as Prime Minister David Cameron will continue to lay his wreath on his own.
A Buckingham Palace spokesman said: "The format for this year's Service of Remembrance at the Cenotaph on November 8 has been reviewed.
"Consideration was given to whether the service format might allow the march-past of veterans to start earlier. A number of veterans wait some time for the parade to move off, and then have a lengthy march to Horse Guards Parade.
"This year, in order to allow the parade to get under way earlier, some members of the Royal Family and political figures will lay their wreaths simultaneously. These changes will be put in place by the Department of Culture, Media and Sport following discussion with the Royal Household."
In the new format, Labour leader Jeremy Corbyn, the SNP's Westminster leader Angus Robertson, the DUP's Nigel Dodds and Liberal Democrat leader Tim Farron will lay their wreaths together.
The Times reported that Downing Street is under pressure to reconsider the plans because of the prominent role given to Mr Cameron.
Former SNP leader Alex Salmond told the newspaper: "The Remembrance Day service has been supported on an all-party basis since just after the First World War. I would advise the Government and everyone else connected that it is not in anyone's interest to tamper with it.
"It is the ceremony with the utmost solemnity and dignity. People thinking about this should also remember it is about service personnel and the families of the fallen, and keep that uppermost in mind."