Schools can choose to postpone the introduction of the controversial new relationships and sex education (RSE) curriculum if they do not feel ready, the Government has said.
While the curriculum will still be compulsory from September, schools will have some flexibility over its introduction if they feel unprepared because of the challenges brought on by coronavirus.
In a notice to schools, the Department for Education said the implementation of the curriculum could be delayed until summer 2021.
"Following the decision to close schools for the majority of pupils, the Department has been working to assess the immediate and long term impact of coronavirus on education delivery, including the implications on a school's ability to discharge their duty relating to the implementation of these subjects," it said.
"The Department remains committed to supporting all schools in their preparations to deliver these subjects. In light of these circumstances, the Department wants to reassure schools that they have flexibility over how they discharge their duty within the first year of compulsory teaching.
"Schools who assess that they are prepared to deliver teaching and have met the requirements set out in the statutory guidance are encouraged to begin delivering teaching from 1 September 2020, or whenever is practicable to do so within the first few weeks of the new school year.
"Schools that assess that they have been unable to adequately meet the requirements because of the lost time and competing priorities should aim to start preparations to deliver the new curriculum and to commence teaching the new content no later than the start of the summer term 2021."
The Government is making relationships education compulsory for primary-aged children, and relationships and sex education (RSE) mandatory for secondary students.
Until now, parents could withdraw their children from sex education up to the age of 18 but this is being lowered to 15.
The new RSE curriculum has been strongly criticised by Christian groups, including Christian Concern and The Christian Institute.
They fear that the lessons, which will cover a range of topics like like homosexuality and transgenderism, may not be age appropriate and could sexualise children.
Christian Concern called the delay to the roll-out a "victory for parental rights". It is asking parents to learn more about their rights surrounding the curriculum, and contact schools to express their support for the delay.
"Know your rights and know that you can make a difference in your child's education," it said.