A Christian barrister has written to the College of Policing urging it to adopt a 'Street Preacher's Charter' in an attempt to stop more evangelists being arrested.
A string of arrests involving street preachers in recent years has given rise to concerns over free speech.
Often the street preachers have been arrested and then released without charge or later exonerated in the courts.
Barrister Paul Diamond blamed the arrests on hate crime laws and overstretched police departments resulting in fewer officers on the beat.
In a letter to Chief Constable Andy Marsh, CEO of the College of Policing, he said police were being put in the "impossible position" of trying to balance free speech with their duty to maintain public order.
But he also suggested that the reputation of the police was being damaged by high profile cases involving street preachers, and that police would benefit from being better informed about religious language.
He said that free speech must include "the right to offend".
"Police officers are hard-working, committed individuals seeking to improve the lives of law-abiding members of the community," he said.
"Often, they are placed in an impossible position; they have a responsibility to protect free speech, a duty to maintain public order and under pressure to silence unpopular speech."
Mr Diamond has offered to work with the police in formulating a charter clarifying guidance on the law in relation to religious rights and free speech, particularly where these concern the issues of sexuality and other faiths.
The charter would also be signed by street preachers to show that they understand the law as well as the police's responsibilities.
He said a charter would ensure consistency in the way that police across the country handle issues relating to religious freedom and free speech, while also improving the relationship between street preachers and their local constabularies.
He added, "Officers work under pressure; and are not versed often in the religious language used by street preachers.
"The arrest of street preachers has become another controversial field; often resulting in negative press coverage of the acts of the police."