More prescriptive guidance forcing primary heads to teach about LGBT relationships would not have prevented protests outside schools in Birmingham, the schools minister has said.

Nick Gibb told the House of Commons today that new statutory guidance on relationships and sex education deliberately left it up to schools when to teach about LGBT issues in order to achieve “consensus” and to get the changes through Parliament.

New relationships education lessons will become compulsory in all schools from next September, while all secondary schools will also have to teach sex education.

The guidance, which is statutory for schools, states that LGBT issues must be covered, but that it is up to school leaders to decide when it is “appropriate” to do so.

Campaigners and opposition MPs claim a lack of stronger guidance has exacerbated protests against existing equalities teaching in several Birmingham schools and left headteachers to deal with parental anger over the policy, rather than ministers.

During a debate on the issue in Parliament today, several MPs called for changes to the guidance to stipulate that primary schools must teach about LGBT relationships.

But responding to such calls from Birmingham Yardley MP Jess Phillips, Gibb remained defiant.

“I don’t believe that that would have prevented the protests that she is seeing at the Birmingham school,” he said.

“There is a segment of opinion on either end of this debate that will not be persuaded of the appropriateness of this guidance. There are some people who will never agree to LGBT issues being taught in schools. So as such I do not believe requiring it in the way the honourable lady says in the guidance to be taught at a specific age in primary schools would have had any impact at all on preventing those protests.”

Gibb said he had been “absolutely clear” that the government supports “schools and headteachers of primary schools that wish to teach LGBT relationships to children in our schools”.

He also pledged to back councils that take legal action to prevent protests “that have turned into intimidation against young people”, as the government did with Birmingham council’s recent injunction against protesters at Anderton Park primary school.

But the minister warned that the government’s reforms may not have become a reality had the guidance been more prescriptive, because some schools and politicians would have opposed a harder line.

“If we had taken her advice, we would not have had the consensus for this statutory guidance, there would have been opponents of the regulations as we took it through this house and [the House of Lords] and we would not have been able to achieve acceptance by a whole raft of independent private schools that we want to be included as subject to this statutory guidance.”