The move follows Alan Milburn's interim report on youth unemployment last week which highlighted the importance of work experience.
Work and pensions secretary Pat McFadden said: ‘The evidence is clear, give young people real work experience and the chances of them building a lasting career increase dramatically.
‘That's why we are creating 300,000 new placements, backed by some of Britain's biggest employers, to give young people the skills, confidence and connections they need to get on.
‘This generation deserves every opportunity to succeed, and this Government is determined to deliver it.'
The 300,000 placements will be made up of work experience and Sector-based Work Academy Programmes (SWAPs) for jobseekers claiming benefits, which offer training, hands-on experience of the workplace and a guaranteed job interview.
Recent analysis shows around four in ten SWAP participants move into sustained work within six months, earning an average of £1,400 a month.
