Prime Minister David Cameron has defended the Government's plans to scrap the Education Maintenance Allowance (EMA), but insisted that he wants more pupils to stay in school.

The EMA is a weekly payment of between £10 and £30 given to the poorest 16 to 18-year-olds, living in households earning under £30,800 a year, to encourage them to stay in education.

Mr Cameron said: "The problem, as you know, that we have is that we want more people to stay on in school but we have to look at the current system and how it's working.

"The last Labour government commissioned research and found that 90 per cent of those on EMA would be attending school in any event.

"And we've also got to look at the context in which EMAs were introduced to this country."

Campaigners have warned that a generation will be "consigned to the scrapheap of activity" if a grant for the poorest teenagers is axed.

Protestors are due to start demonstrating at Piccadilly from 4pm till 5pm. They are expected to stop at Parliament Square, where a rally will commence.

Education Activist Network spokesman, Mark Bergfeld, has confirmed that EMA students and further education lecturers are expected to speak.

The Government has announced the grant is to be withdrawn and it has already been closed to new applicants.