A Remembrance Sunday service at the Harrow Green cenotaph on High Road Leytonstone was overshadowed by a confrontation over white poppies.
Captain Alastair Martin, a Royal Anglian Regiment veteran who served in Bosnia and Northern Ireland, confronted Green councillor RoseMary Warrington as she prepared to lay a white poppy wreath.
"You are being deeply disrespectful in what you're doing," he told her. He later called her "a disgrace". Cllr Warrington is said to have replied that Captain Martin was "only here to glorify war".
Captain Martin described the white poppy as "a political symbol", unlike the red poppy, which he said involves "no politics". He called laying the white wreath "an act of sabotage" and suggested white poppies should be kept for International Peace Day on 21 September rather than worn during the remembrance season.
Cllr Warrington declined to comment. Her fellow Green councillor Peter Richardson said they had included white poppies "as a respectful call for peace and a remembrance of the civilian casualties of war". He said this message was in keeping with the sermons and hymns at the service.
White poppies are produced by the Peace Pledge Union, which was founded in 1934. They stand for opposition to all war and for remembering civilian casualties.
In a YouGov survey of 8,024 UK adults, 64% said wearing a white poppy during the remembrance season was acceptable, and 15% said it was not.