Residents, council staff and councillors have been subject to rising “abuse, harassment and intimidation” directly linked to the removal of unauthorised flags, a local authority has said.

Shropshire council said it had recorded a rise in reports of abuse with staff and members “being threatened for explaining the council’s position” on the removal of flags and when they attempt to do so – “even in day-to-day work to repair street lighting”, the authority added.

The flag campaign, which is believed to have started in Birmingham last summer, has resulted in hundreds of union and St George’s flags being erected on lamp-posts, roundabouts and street furniture across England.

Groups involved have said the flags are symbols of pride and patriotism. However, some charities and MPs have raised concerns that the campaign is an act of intimidation and heightens tensions between communities.

Shropshire council previously said it would not “police people” over the issue, but last month said the flags would be taken down due to safety concerns. Those involved in erecting the flags would be pursued for the costs of their removal, the authority added.

A spokesperson for Shropshire council said on Sunday that the union flag was a “national emblem” that was “widely respected” but acknowledged there were a “range of views about the flags” and it aimed to balance those opinions.

“We do not, however, support the unauthorised attachment of flags or any other objects to street lighting columns, highway infrastructure or other public street furniture due to health and safety issues, damage and costs to residents,” a spokesperson said, encouraging those subject to abuse to report it to the police.

They added: “Removing flags is not normal council business, it is not a statutory service and therefore it comes at an additional cost to the council and its residents.”

The council, which recently increased council tax by 9% in an effort to balance its budget, previously said the cost of removing unauthorised flags after Storm Amy in October was £13,000.

This prompted a group involved in hanging flags in Shrewsbury to offer to take them down for free to save the council money.

Oxfordshire council has also said its staff and local residents had reported “abuse and threatening behaviour” over the removal of flags. The council issued a formal legal notice to the Raise The Colours group in an attempt to stop people from erecting flags in the area.

The leader of the council, Liz Leffman, said at the end of March: “The scale and persistence of this activity is affecting communities across Oxfordshire … It is an act of intimidation and division that is having a real and damaging impact on our communities.

“Our residents report feeling distressed, unwelcome and unsafe in their own neighbourhoods. Our teams removing the flags, together with residents who have challenged the individuals installing them, have been subject to abuse and threatening behaviour. This is totally unacceptable.”

Raise The Colours previously said it encouraged people to display the flag as a “symbol of unity and shared identity”.