A Lords amendment proposing to drop “insulting” behaviour from Section 5 of the Public Order Act, which has been used by lawyers to prosecute both homophobic religious preachers and gay rights campaigners, has won government approval.

On Monday, Home Secretary Theresa May promised that the government would not seek to overturn the amendment, which will change the statement “A person is guilty of an offence if he uses threatening, abusive or insulting words or behaviour” to no longer include the word  “insulting”.

The House of Lords voted 150-54 in favour of the decision for England and Wales in December of last year.

Mrs May said: “I respect the review taken by their Lordships. They had concerns which I know are shared by some in this House that Section 5 encroaches upon freedom of expression.

“On the other hand, the view expressed by many in the police is that Section 5 including the word insulting is a valuable tool in helping them keep the peace and maintain public order.

“Now there’s always a careful balance to be struck between protecting our proud tradition of free speech and taking action against those who cause widespread offence with their actions.”

Labour have criticised the move, saying that it will remove protection from minority groups.

Shadow home secretary Yvette Cooper said: “It is important to make sure we can protect freedom of speech but it is also very important to make sure we can protect vulnerable groups from unfair discrimination.”

Section 5 has been the subject of criticism for enabling spurious arrests due to the subjectivity of what counts as an insult.

The Act has previously been used against a student who joked that a police horse was gay, a pensioner who said that religious beliefs were fairy stories, a street preacher who criticised homosexuality as immoral and a youth who condemned Scientology as a dangerous cult.

Campaigns to amend the Act drew support from a wide range of groups including religious organisations, the National Secular Society, celebrities, and human rights foundations.

Human rights activist Peter Tatchell was among the most prominent supporters. Mr Tatchell took part in a Section 5 protest outside parliament in 2012.

Later that year Mr Tatchell also condemned the treatment of Barry Thew, who was arrested for wearing a t-shirt that was deemed insulting to police.

Mr Threw displayed the t-shirt just hours after PC’s Fiona Bone and Nicola Hughes were murdered in Greater Manchester.

In October, Mr Tatchell said: “The price of free speech is that we sometimes have to put up with views we find offensive.

“Insults are not nice and I would discourage them. But they should not be crimes”.