The National Council for Voluntary Organisations has called for "byzantine" EU regulation to be simplified so that it no longer hinders charities.
In its manifesto, Towards a More Open Europe, published before the European Parliament elections on 22 May, the umbrella body calls for EU institutions to be reformed to make them more transparent and accountable, and says resources should be focused on the most urgent social and environmental goals.
In his foreword to the document, Sir Stuart Etherington, chief executive of the NCVO, says: "I am in no doubt that membership of the European Union is in the best interests of the UK. But the need for reform is now both urgent and compelling."
The manifesto says EU funding can often seem impenetrable to many voluntary organisations.
"The reporting requirements are often byzantine, with such rules as maintaining records of bus tickets for up to 20 years," it says. "Furthermore, the size of contracts has often limited opportunities for smaller organisations to engage with these funds."
It calls for the funds to be presented in a more accessible and less bureaucratic format, with smaller grants available.
The NCVO calls for EU regulation to continue to be reviewed and simplified to enable community-led service delivery. It says the regulation is often overly complex and poorly understood by the voluntary sector.
"EU institutions are seen as distant from the everyday lives of many people, and their decision-making processes are often perceived as opaque and slow-moving," the document says. It calls for decision-making in key institutions to be more open and transparent.
It says an EU framework for better partnership working between European institutions and charities is needed. It would work in a similar way to the Compacts established in the UK, Sweden, Estonia and Slovenia, which set out guidelines for working between governments and the voluntary sector.
The NCVO first proposed a European Compact in 2009 and said last year it was close to becoming a reality.
Etherington said in a statement: "Civil society has a role to play in addressing many of the problems facing the UK and other countries across Europe. EU rules influence our activities and the way in which we can respond to these challenges. It is crucial that they provide a supportive environment, rather than a barrier to getting things done.
"We want to see renewal of EU spending to focus resources on inclusive growth that addresses the most urgent social and environmental goals; simplified EU regulation to ensure that EU rules benefit rather than hinder voluntary organisations; and reform of the EU’s institutions to improve dialogue and accountability."
The NCVO’s recommendations will be promoted among all candidates before the elections.