Mr Johnson, who will visit a primary school in London on Tuesday, said thousands of new free school places would “help to ensure children are getting the best education possible”.
But the National Education Union (NEU) said the Government was pursuing a “reckless approach” by “throwing taxpayers’ money at its pet project”, saying the free schools programme is “in crisis”.
The latest round of applications could see up to 30 schools selected, and the Government wants applications from parts of the country which have no free schools, as well as alternative provision and special schools.
Mr Johnson said: “Free schools help to ensure children are getting the best education possible – offering exceptional teaching, encouraging strong discipline and providing families with more choices.
“I want to see even more of these excellent schools open, particularly in areas most in need of more good and outstanding school places.”
Free schools – new state schools that are not under local council control – are a key part of Conservative education policy.
They are typically set up by groups like teachers, parents, charities, businesses or trusts, are directly funded by Government, and have freedom over areas such as the curriculum and staff pay.
Since the programme began it has faced controversy, with supporters arguing that free schools give parents more choice and help drive up standards, and critics raising concerns they are more likely to be in middle-class areas, with poorer youngsters missing out.
According to the Department for Education (DfE), more than 500 free schools have opened since 2010, creating more than 133,000 school places, with more than 220 set to open in the coming years.
Of those inspected by Ofsted, 84% have been rated good or outstanding, with 30% rated outstanding, the DoE added.
But Dr Mary Bousted, joint general secretary of the NEU, said: “Once again, this Government is throwing taxpayers’ money at its pet project free schools, instead of taking a long hard look at where investment is most needed, after a decade in which schools across England have been starved of cash.
“The Government’s academy and free schools programme is in crisis.
“Once the 23 free schools that have had to close due to serious failings are factored in, free schools are less likely to be rated good or outstanding by Ofsted than other state-funded schools.
“Furthermore, free schools are far more likely to be judged requires improvement or inadequate than other state schools.”
The Government has pledged to invest more than £14 billion in primary and secondary education between now and 2022-23.