David Cameron's flagship Big Society project lacks a clear vision and strategy and is being hampered by widespread cuts, according to an independent audit of the first two years of the initiative.
A report by think tank Civil Exchange also identified a widening "big society gap" between affluent and disadvantaged areas in England as a result of the Government's austerity measures.
It said a number of leadership and operational issues are emerging which "threaten the ultimate success of the initiative".
The study tested progress on the "three pillars" of the big society policy launched in 2010 by Mr Cameron: enabling people to shape their local area; opening up public services provision to charities' and levels of "social action" such as volunteering.
After drawing on more than 40 data sources, it concluded that "an urgent, genuine step change in how central Government and civil society work together" was needed.
The report said: "If the Big Society is to succeed, the Government must do more to work with the voluntary sector to build a common vision and goals.
"Far from being strengthened in the first two years of the Big Society, the voluntary sector is now facing an estimated cut in statutory funding of £3.3 billion between 2010-16, a gap which is unlikely to be filled by increased donations."
Civil Exchange said the cuts have hit disadvantaged areas, where voluntary organisations tend to be more involved in the delivery of public services, the hardest.
It said that groups in these areas were more likely to be reliant on state funding than in affluent areas, which have stronger levels of community empowerment and greater levels of social action.
Civil Exchange's director Caroline Slocock, the principle author of the report, said: "The Audit finds a 'Big Society gap' in performance against key indicators between younger and older people, affluent and disadvantaged communities, rural and urban areas and white and ethnic minority people.
"Targeted support to reduce this gap is needed but voluntary sector capacity in key communities is likely to have been undermined by cuts in public funding, which have fallen particularly heavily in disadvantaged areas."
The report recommended that the Big Society project should particularly focus on disadvantaged communities, urban areas and younger people.
And it called on central Government to work closer with partners from the voluntary sector to forge a stronger vision for the policy.
It also said the voluntary sectors should play a greater role in delivering public services, with the bias currently in favour of the private sector.
SUBSCRIBE AND FOLLOW
Get top stories and blog posts emailed to me each day. Newsletters may offer personalized content or advertisements.Learn more