In March, the Government will withdraw funding worth £540,000 from networks in the nine English regions, which it has provided most of the funding for since their creation in 1999. The Office of the Third Sector now oversees the funding.
In a paper outlining its opposition to the decision, Voice4Change warned that if the decision ends in the networks' closure, it will damage the Government's ability to work with up to 15,000 organisations delivering services to BME communities.
"The Office of the Third Sector must recognise that the generic VCS networks and infrastructure organisations, at whatever level, still do not have the skills, understanding, time, resources or reach to act as an effective or trusted voice for the BME voluntary sector," Voice4Change said.
"Strong BME infrastructure organisations simply do not always exist elsewhere, such as at a local or sub-regional level. Consequently, the work of the BME regional networks is highly valued and remains necessary."
Scrapping the networks would make it more difficult for the Government to talk to minority organisations and to develop coherent equality and inclusion policies, Voice4Change said.
It said that BME communities often did not receive good levels of services and BME voluntary organisations still found it difficult to get access to mainstream funding, and that the networks were needed to fight against these problems.
It will also make it more difficult for minority organisations to organise themselves on a strategic level and speak with a single voice, it added.
"Unless funding for the BME regional networks continues, the essential function they perform in speaking up for BME communities and helping the Government deliver on its equalities programmes will be lost," said Vandna Gohil, director of Voice4Change England.
"The BME third sector has been historically under-resourced and in the current economic climate is likely to be further pressed by the decline in grant-making."
A spokesman for the Office of the Third Sector said it was considering the role of the networks and would make an announcement in due course.