Derby City Council has said it has removed about 950 flags from public spaces.
The Labour-run authority said in September that it would begin removing flags put up on bridges, walls and lamp-posts.
In a statement, councillor Sarah Chambers previously said it was time to bring the “campaign of flag flying to an end” but she “fully” supported those who chose to fly flags on their own property.
A city council spokesperson said: “As part of our statutory responsibility to keep public spaces safe and well-maintained, we are continuing to remove unauthorised flags from lamp-posts.”
The flag movement gathered pace on social media, with the name Operation Raise the Colours.
Those behind it said they were motivated by pride and patriotism.
Others have expressed discomfort due to tensions running high across England over immigration and the St George cross often being used to promote far-right groups.
The Local Democracy Reporting Service said the council had appointed security guards in response to “threatening behaviour” towards contractors.
A Derby City Council spokesperson previously said: “In late November, third-party security was appointed by the council to ensure the safety of our street lighting contractors when removing flags from public areas.
“This is in response to multiple incidents of threatening behaviour and threats towards contractors simply doing their jobs.
“The council absolutely condemns this behaviour and believes that people have a right to carry out their roles safely and without fear.”