Future First appeals for past students to go back to their former schools to act as role models who the present pupils can relate to.
The charity is now working with almost 500 schools across the country including 20 in Yorkshire.
The idea is for a school’s alumni to provide support by giving talks about their own career, mentoring pupils, providing work experience or contributing to a school as a donor or governor.
Lawnswood School, in Leeds, and Thomas Rotherham College, in Rotherham, are the latest to sign up to the programme.
Future First managing director Alex Shapland-Howes said: “We take people in jobs back to their old school or college, like Lawnswood School in Leeds and Thomas Rotherham College in Rotherham, to act as relatable role models for the young people still there. The schools then harness the talents of alumni.
“If someone who sat in the same hall or kicked a ball in the same park has gone on to achieve, students are more likely to believe they can too.
“You don’t need to be a celebrity or have a flashy job to be an inspirational career model. By going back to talk to students about the path you’ve followed since you left and the lessons you have learned – especially the tough ones – you can transform young people’s perceptions about what ‘people like them’ go on to do.
The charity is now appealing for former pupils of Thomas Rotherham and Lawnswood or the latter’s predecessors, Lawnswood High School for Girls and Leeds Modern, to come forward.
Mr Shapland Howes added: “More than nine in 10 people in this country walk out of their school after their last exam and never ever go back. This is a massive wasted opportunity.”
He said Future First could help shape people’s careers by showing them positive role models who have come from the same background as them.
He warned that in some cases up to half the pupils from the poorest backgrounds in the country do not know anyone who works in the career or job that they want to go into.
He added: “ Nearly 83 per cent of schools are operating a reduced careers service. Research by Future First shows that 39 per cent of students don’t even know anyone in a job they’d like to do, rising to 45 per cent among free school meals students.
“If they see that someone who went to the same school and grew up in the same community has achieved a fulfilling and satisfying job, it helps them see it’s possible for them too.
“It’s really important for all students to be motivated to succeed in the working world and hearing first hand from people they can relate to who are now working in interesting jobs can make a huge difference.”
Future First is now working with 20 schools across Yorkshire including Wakefield City Academy, Mirfield Free Grammar School, Abbey Grange Academy, in Leeds, Moor End Academy, in Huddersfield, Laisterdyke Business and Enterprise College, Oasis Academy Lister Park and Buttershaw Business and Enterprise College, which are all in Bradford.
Lawnswood’s headteacher, Simon White, said “We signed up to Future First’s scheme as soon as we knew of it. A network of past pupils with all their valuable experience would greatly help us to broaden current pupils’ job horizons and equip them for the world of work.”