Roger Lyons, joint general secretary of Amicus, was speaking at the House of Commons last week at the launch of a new charter intended to guarantee better treatment for workers and volunteers in the non-profit sector.
"Voluntary organisations often bring together ordinary people to achieve extraordinary outcomes," he said. "But ordinary people who make the effort, who pull out the stops and get the job done when there is not much to work with, can easily be exploited."
The charter says that organisations should develop fair and effective HR policies, consult with staff and volunteers, plan budgets to include employee benefits, and recognise the right of workers to join unions.
According to Amicus, twice as many workers from voluntary organisations make appeals to employment tribunals for unfair treatment than the average for the workforce as a whole.
The union, which represents around 30,000 workers in the voluntary sector and has recognition agreements with major charities such as NCH and the RSPCA, wants the charter to be adopted by the sector as a whole.
Reading Council has already signed up to it and will not award funding to any organisation that does not agree to its terms.
Unionisation is comparatively low in the voluntary sector with just 15 per cent of charity workers members of unions.
Lyons said incidents of bad treatment were due to a variety of reasons: "More often than not it is a question of resources. Sometimes it is because of lack of skilled HR management. Often it is because high ideals, overload and stress and too little time to consider the needs of working people.
But neglect their needs at your peril."
Chris Ball, voluntary sector secretary with Amicus, said the charter was especially targeted at small- and medium-sized locally funded organisations "where issues of funding and insecurity are a problem".
He said the charter was an attempt to fill a gap in the Compact - the series of agreements between the Government and voluntary sector. It could be adopted as part of local compacts, as in the Reading case, or eventually formally adopted as part of the national Compact.
The eight point charter was developed in conjunction with the Amicus Parliamentary committee chaired by MP Des Turner.