In an open letter to NCS leaders, Brendan O'Keefe, who established one of the first staff-led youth mutuals in England when Epic Community Interest Company (CIC) took on responsibility for services in Kensington and Chelsea in 2014, said the organisation running the NCS, the NCS Trust, should "open up more" and address the "rigidity" of its operating model.
The government's flagship youth volunteering scheme faced questions from members of the public accounts select committee earlier this month, after its report raised concerns regarding the programme's cost.
NCS has received £475m of public funding since 2014/15, but MPs argued its costs were higher than for comparable youth schemes, and that it was exceeding the £1,562 per participant spend implied in the autumn 2015 Spending Review by paying out £1,863 for each participant in 2016.
National Audit Office research published in January showed the scheme was on track to miss a participation target set for 2020/21 by 34,000, despite that goal having previously been revised down.
In his letter O'Keefe said organisations such as Epic CIC could help NCS achieve participation targets because they had local networks and understood communities.
"If you can find a way of working better with locally based community groups like us, we will help you to smash your challenging participation targets," he said.
O'Keefe also argued youth organisations could help NCS track long-term impact, and deliver better value for money.
"Because community groups often work with young people over a longer period of time, sometimes years, we can help you to improve the way you track long-term impact," he said.
"Our costs per head are less than half of yours for an all year-round service."
In the letter, O'Keefe also expressed a desire for NCS to look upon other youth organisations as "friends", despite potentially feeling hostility from those who have resented its receipt of government funding while themselves facing cuts.
"Let your friends in the sector help," he said.
"Too many young people are missing out on a potentially life-changing opportunity. We want to help and the door is open."
Michael Lynas, chief executive of the NCS Trust, said: "As we look to the future we want more organisations to join us and help further deepen our reach, impact and value for money.
"That's why we partnered with a range of organisations including local authorities, Sea Cadets and fire and rescue services to deliver pathfinder programmes last autumn, and why we are currently building more innovative partnerships with a range of organisations.
"We encourage EPIC and all other organisations that are passionate about young people to get in touch to discuss how we can partner together as we recommision and strengthen our network for the future."
