An exhibition in Sheffield by followers of the controversial Scientology religion prompted complaints from some members of the public.
Scientologists - whose celebrity members include Tom Cruise and John Travolta - set up a bright yellow tent in Barker's Pool to educate people about the religion.
But critics have dubbed the religion a "cult" and Star reader Mark Nuttall said he thought it was "appalling" Sheffield Council had given the Scientologists permission to set up the tent.
He said: "I would like to know how the decision was made that allowed Scientologists to set up a recruitment tent in Barker's Pool in the school holidays.
"Someone, whether the council or the police, must intervene and stop these people before they manage to influence vulnerable teenagers." The Scientologists said the marquee was to provide information about the practical work they do - including helping victims of the 2007 floods in Yorkshire.
Spokesman Sam Butler said: "The exhibition provided information about the practical help we can provide, not only to assist in major disasters but to help with everyday 'disasters' like marriage difficulties and conflicts at work.
"Visitors to the marquee were offered 'assists' - simple procedures to alleviate aches and pains - and booklets.
"The Volunteer Ministers toured around 1,000 people through the exhibition and help was directly provided to more than 400 members of the public.
"Those receiving help are not asked to become Scientologists.
"One person voicing disagreements with the help and information being provided to hundreds will not dissuade our volunteers from offering such help.
"The schedule for the travelling exhibition is planned around the availability of locations across the country and does not follow the public or school holiday calendar."
Sheffield Council said it does not judge whether the views of a religion are right or wrong.
A spokesman said: "When booking space in the city centre we ensure all exhibiting organisations comply with health and safety guidelines and are not promoting products of a harmful, undesirable or offensive nature.
"The Scientologists provided all necessary legal documentation, and met the relevant criteria, and were therefore given permission to use the promotional space.
"We would apply the same policy to all religious organisations wanting to have a city centre presence, and treat each application individually in terms of its compliance with our policy."
