Boris Johnson has been forced to defend plans to increase powers for Ofsted school inspectors amid claims teachers are already caving under enough mounting pressure.
But, he insisted no-notice school inspections and longer, more intensive visits were not "Draconian".
He said: "They won't be more Draconian... the intention is to support teachers and what we want to see is increased funding for teachers, increased funding for teachers' salaries, increased funding for schools."
Mr Johnson also weighed in on the ongoing thorny issue of teaching LGBT values in the classroom - a subject that has sparked many protests and court challenges.
The prime minister told ITV News that it was "unequivocally right" that children should be taught about LBGT issues.
Mr Johnson said a Conservative majority government would invest in education and schools to back teachers.
"I think teachers are doing an incredible job. I think there a very many schools that have good or outstanding results," he said.
"It's right to do as much as we can to encourage good performance - that's why I want to strengthen Ofsted and give it more powers - and the reason for that is not to put more pressure on teachers but just to give parents the security and the sense that not only is their school aiming for high standards but it's also a place where their kids are very safe."
When pressed on whether he was essentially telling teachers to spend more time on inspections, rather than simply getting on with the job in the classroom, he said: "They do a fantastic job - we emphatically do not want to increase stress levels.
"Again, I don't think Draconian is the right word for what we want to do, we want to be supportive of teachers, supportive of their fantastic work."
The Conservative plan includes:
Longer inspections to be sure of the full breadth of a school’s activity. The length of annual inspections in secondary schools and large primary schools will be upped from two to three days – with the extra day to focus on behaviour to reassure parents that all aspects of their child’s school are properly evaluated.
No-notice inspections to ensure inspections truly reflect the day to day experience in schools.
£10 million additional funding to back Ofsted. This money will support the training and deployment of more inspectors.
End of outstanding exemption. Rules will be changed so that outstanding schools are also subject to routine inspections.
The proposals contrast to that of Labour, which is proposing to scrap Ofsted.
Mr Johnson said: "I think just abolishing Ofsted which, I think is the policy of Mr Corbyn and the Labour Party, getting rid of inspections, allowing local authorities effectively to mark their own homework and announce that all their schools are doing terrifically well - I don't think that will give parents the security and confidence they need.
"It won't be Draconian, it will be humane, respectful and it will be encouraging."
The Prime Minister's announcement was attacked by the head of a teaching union.
Paul Whiteman, General Secretary of National Association of Headteachers (NAHT) which represents around 28,500 people slammed the plan as "disappointing" and a bid to "catch eyes during an election campaign".
"It's not inspections that improve schools, more inspections will do nothing to tell us what we already know - that 85% of children are taught in schools that are good or better already," Mr Whiteman told ITV News.
He claimed inspections are already "driving teachers away from the profession" and any increase would "fly in the face of some of the progress we were making with the Government before Parliament was dissolved".
"We simply can't recruit enough teachers into the system and many many more are leaving because of the pressure of teaching and the teaching system, and a lot of that is down to the high-stakes nature of inspection.
"We need to free the profession to be the real high-standard professionals that they are: to be innovative and to truly improve schools, not to be Ofsted ready."
During the interview, Mr Johnson was also asked about LGBT teaching.
"I think it's very important that every kid, every pupil should be taught about the world in which they're going to find themselves when they leave school and indeed, the world they find themselves at school.
"People have their own views and they have a right to express their views but I don't think they have the right to disrupt teaching and education and I think we should carry on with confidence and determination and insist on our values because they're entirely right."
He was surprised to hear that a school in Birmingham may have been pressured to stop teaching LGBT values.