Theresa May has insisted she has a mandate for her controversial plans to shake up England's schools.
The Prime Minister, who has indicated she will not hold a snap election after taking over from David Cameron at Number 10, insisted her leadership is based on the 2015 Conservative manifesto.
Her plans for new grammar schools have been criticised by Tory former education secretary Nicky Morgan and the Prime Minister will face a stiff test to get them through Parliament.
The House of Lords could prove a barrier to the reforms because peers will not feel obliged to give way if the plans were not part of the pitch to voters at a general election.
But Mrs May has claimed the basis for her plan is the 2015 Tory manifesto which saw David Cameron win with a slender majority.
Defending her plans during a visit to the United Nations in New York, she told broadcasters: "I and every Conservative member of parliament who was elected in 2015 stood on a manifesto commitment to increase the number of excellent school places for children. There are one and a quarter million children who are not in schools that are good or outstanding.
"We need to increase the number of good school places, so what we want to do as a Government is ensure that universities are taking more of a role in supporting schools and opening schools, that there's more of a contribution from the independent sector, that we increase the number of faith schools and, yes, that we lift the ban on people setting up or expanding selective schools.
"But those schools that are set up will need to be able to show that they are genuinely raising the quality of education in an area and ensuring that young people get the opportunity to go as far as their talents will take them."
The Tory manifesto said: "We will continue to allow all good schools to expand, whether they are maintained schools, academies, free schools or grammar schools."
In his foreword to the document, former prime minister Mr Cameron promised voters: "For your child, there will be a place at an excellent school."