Cymuned - "community" in Welsh - will campaign for the preservation of the language in its heartlands by giving locals priority on housing and job lists.
The group has been founded by academics and poets who believe the language will die out within 10 years if steps are not taken, and is the result of months of debate and consultation.
Cymuned has accused the Welsh Assembly of failing to address the decline of Welsh in its heartlands.
The group will call on national and local politicians to use "crisis measures" to deal with the migration of English speakers to Welsh-speaking parts of Wales.
Robat Gruffudd, founder of Welsh publishing house Lolfa, said: "We will campaign on the preservation of Welsh as a community language, concentrating on issues such as in-migration to Welsh-speaking Wales; out-migration, especially of young people; and the assimilation of non-Welsh-speaking in-migrants."
The group also includes poets Iwan Llwyd and Myrddin ap Dafydd, former Welsh Language Society chairman R. Arwel Jones, Barn magazine editor Simon Brooks, Cardiff University lecturer Jerry Hunter, actress Judith Humphreys and former BBC head of light entertainment Meredydd Evans.
It reads: "We are convinced that the death of Welsh as a community language is inevitable within ten years, unless urgent steps are taken to reverse current trends.
"We accuse the political parties, and national institutions, including the National Assembly, of failing to address this crisis.
"We call on these bodies, and the Assembly and county councils in particular, to implement national crisis measures as a matter of urgency to halt the decline of Welsh in its heartlands.
Cymuned also sets out to "tackle the huge in-migration of monoglot English speakers to Welsh-speaking areas by establishing community control of housing policy in these areas".
Members have also called for action to stop Welsh speakers leaving their homes "by giving local people priority in the housing market and creating suitable employment for them."