Labour and the Greens are outraged by the Government's decision to postpone its review of the Charities Act.
Cabinet decided in 2010 to begin the review in 2013 and complete it by 2015, but Community and Voluntary Sector Minister Jo Goodhew says the time isn't right.
The Government considered limiting it to the definition of charities, but widening the definition would be limited by tax implications in tight financial circumstances, she said on Friday.
"The current definition is still working reasonably well so the need for a review is not pressing," she said.
"I will reconsider a review of the definition once the fiscal situation has improved."
Labour says Ms Goodhew knows there are serious problems with the definition.
"She also knows that at the moment big commercial enterprises are able to channel tax benefits into private hands, while small community-based groups, working at grass roots level, are being refused registration," said community and voluntary sector spokeswoman Louisa Wall.
"It's appalling for the government to treat the community and voluntary sector in such a disrespectful manner."
The Greens say the Government doesn't want to give up any tax revenue.
"This is another blow to the community and voluntary sector," MP Denise Roche said.
"The Government says an increase in the number of registered charities might lessen tax revenue, however it is likely the review would weed out some significant commercial enterprises that are currently registered as charities and channel tax benefits into private hands."