Signs have been put up in a city centre reminding people not to relieve themselves in public places.
They are part of a new Public Space Protection Order (PSPO) zone created by Peterborough City Council, which can now impose on-the-spot fines.
Defecation was included on signs after residents raised concerns.
"It's a very sad indictment on our society that people have to be reminded not to defecate in a public place," said John Read from Clean Up Britain.
"It's ridiculous for councils to have to waste money putting up these sort of signs, but the same very much applies to litter and fly-tipping.
"I'm afraid it seems to be symptomatic of a decline in community pride and respect for the wider environment."
The signs were put up this week as part of the PSPO, the second in Peterborough, which covers much of the city centre and parks where defecation has been highlighted as an issue.
"Both PSPOs cover a range of anti-social behaviour and were developed in consultation with the public," a city council prevention and enforcement service spokeswoman said.
"We expect the majority of fines to be issued for littering which is the main problem in both areas."