Parents Autism Campaign for Education has merged with the TreeHouse Trust, the autism charity whose patrons include newsreader Jon Snow and novelist Nick Hornby.
PACE will now become the trust's policy and campaigning unit. Its director, Virginia Bovell, will remain in charge of the unit, reporting, along with co-director Steve Broach, directly to TreeHouse chief executive Christine Asbury.
The work of the two charities began to overlap when TreeHouse, which runs an educational centre for children with autism, got involved in campaigning.
Bovell, who is a trustee and founding member of TreeHouse, claimed the merger would enable PACE to gain experience in service provision and refute accusations that it is a talking shop.