A US judge has temporarily blocked Obama administration regulations expanding stem cell research.
The non-profit group Nightlight Christian Adoptions contends that the government's new guidelines will decrease the number of human embryos available for adoption.
US District Judge Royce Lamberth ruled that the plaintiffs are entitled to bring their lawsuit in the courts.
A federal appeals court ruled that two doctors who were among those bringing the lawsuit, adult stem cell researchers James Sherely of the Boston Biomedical Research Institute and Theresa Deisher of AVM Biotechnology, had the authority to do so, prompting Judge Lamberth to reverse a decision he made last October.
Nightlight helps individuals adopt human embryos that are being stored in fertilisation clinics.
It began the programme in 1997, using some of more than 400,000 frozen embryos.
Judge Lamberth concluded that those filing the lawsuit demonstrated a strong likelihood of success in arguing that the new government guidelines violate a law that prohibits the use of federal funds for research in which human embryos are destroyed.
