Image copyright PA Image caption David Cameron has announced another 18 free schools

David Cameron is announcing the latest wave of free schools in England, as a step towards his manifesto pledge of 500 more over the next five years.

The prime minister is launching a further 18 of the state-funded schools, set up by academy trusts, community groups, parents and teachers.

Mr Cameron said this would deliver "innovative and exciting schools".

But the National Union of Teachers said the government was "playing politics" with the demand for school places.

The announcement will add to the 252 free schools already open and a further 52 set to open this term, out of a total of about 22,000 schools in the state sector.

'Crystal clear policy'

The Department for Education says the new projects include a school in Solihull for children who have fallen out of mainstream education and the Gipsy Hill Secondary School in south London, which will use a classical model based on "logic, grammar and rhetoric as the foundations of learning".

The Swan School will open in Oxford and the John Donne Primary Free School in Peckham, both supported by local state schools.

Image copyright PA Image caption Tristram Hunt says ministers should address the teacher shortage rather than focus on free schools

"The aim of this policy is crystal clear - to increase the number of good and outstanding school places so that more parents have the security of knowing their child is getting a great education," said Mr Cameron.

The prime minister said he would "not waver in pressing ahead with our plans" to reach the target of an extra 500 free schools.

But Education Secretary Nicky Morgan said there was a "strong pipeline" of quality applications.

She added: "This is about making sure that every child has a good school place to attend with excellent teaching to fulfil their potential."

NUT leader Christine Blower accused the government of "untruths and misrepresentations" about its free-school policy, saying there was no evidence that they were better than other schools.

Growing demand

Ms Blower said the government had had to change the regulations so that all new schools would be designated as free schools to "help David Cameron hit his own target".

Free schools have the same status as academies, operating outside local authority control and not having to follow the national curriculum and having more flexibility over staffing.

The new schools are being announced at a time of growing demand for school places, with a rising population at both primary and secondary levels.

Russell Hobby, general secretary of the National Association of Head Teachers, said: "There is a desperate need for long-term planning that spans all sectors. With the massive increase in pupil numbers and over-stretched budgets, we cannot afford inefficiency and conflict. The government's approach makes this problem worse.

"Until some agency at the local or regional level has the information and the authority to prioritise school places where they are most needed, parents and children will always be unsure that the system will give them what they want."

A report from London Councils says there is a need for 113,000 extra school places in the capital in the next five years, which it says will need additional funding of £1.5bn.

'Bigger problem'

Nick Timothy, director of the New Schools Network which supports the opening of free schools, said: "The fact is, we urgently need more good new schools - not just where there is a shortage of places but where standards have been too low for too long.

"Free schools are better placed to drive up standards and give parents what they want because they give more control to heads, teachers and governors, rather than politicians and bureaucrats."

But the Local Government Association warned of planning problems that could face councils if the opening of free schools was postponed.

The organisation representing councils says any delay in opening should be made known before school places were allocated in the spring.

"When last minute delays are announced by government, it is the council that picks up the pieces to reassure mums and dads that their child will have a place at a school before September," said the LGA's deputy chairman David Simmonds.

Labour's education spokesman Tristram Hunt said the focus on free schools was missing the bigger problem of a teacher recruitment crisis.

"As children begin the new school year, more and more pupils are being taught by non-specialists and supply teachers, due to the teacher recruitment crisis. And shortages in teacher supply are set to get worse. This should be the priority for education ministers," said Mr Hunt.