A group known to be opposed to abortion has joined a forum advising the Government on sexual health.
The Life organisation was appointed this month to the new panel, which replaces the Independent Advisory Group on Sexual Health and HIV.
In contrast, the British Pregnancy Advisory Service (BPAS) has been omitted from the forum despite its position on the previous group.
A Department of Health spokesman said: "To provide balance, it is important that a wide range of interests and views are represented on the Sexual Health Forum.
"Marie Stopes International and the British Pregnancy Advisory Service have similar interests. We offered them shared membership but they declined, and after careful consideration we concluded that it was not feasible to invite both organisations."
Stuart Cowie, Life's head of education, told the Guardian: "We are delighted to be invited into the group, representing views that have not always been around on similar tables in the past."
He said the organisation would seek to build "common ground" with other members of the forum. But former Liberal Democrat MP Evan Harris said Life's presence could prevent the panel from functioning properly.
He told the newspaper: "When you have an organisation campaigning against the law and against current policy on sexual health, which is pro-contraception and about ensuring that abortion is a choice, then the risk is that you prevent the panel being given access to confidential information."
The sexual health forum also consists of representatives from the British Association for Sexual Health and HIV, the Faculty of Sexual and Reproductive Health, the Association of Directors of Public Health and the British HIV Association. Also on the panel are the Terrence Higgins Trust, sexual health charity Brook, the Family Planning Association, the Sex Education Forum and National Children's Bureau.
Ann Furedi, chief executive of BPAS, said the group was "disappointed and troubled" to be "disinvited" from the panel. "We find it puzzling that the Department of Health would want a group that is opposed to abortion and provides no sexual health services on its sexual health forum," she told the Guardian.