LONDON (CNS) – Human embryos injected with animal cells, or chimeras, should be accorded human status under proposals to be considered by the British Parliament in the fall, said the Catholic bishops of England and Wales.

They also said politicians should reconsider a proposed ban on the implantation of chimeras into women.

"In particular, it should not be a crime to transfer them, or other human embryos, to the body of the woman providing the ovum, in cases where a human ovum has been used to create them," the bishops said.

"Such a woman is the genetic mother, or partial mother, of the embryo; should she have a change of heart and wish to carry her child to term, she should not be prevented from doing so," they added.

The bishops' June 20 submission to a parliamentary committee set up to scrutinize the draft Human Tissue and Embryo Bill was prepared by a committee overseen by Archbishop Peter Smith of Cardiff, Wales, chairman of the English and Welsh bishops' Department for Christian Responsibility and Citizenship.

At present it is illegal in Britain to create embryos using a mix of human and animal genetic material, but the government is proposing to allow scientists, for the first time, to create human-animal embryos for research as long as they are destroyed within two weeks.

In their submission, the bishops said that most of the procedures covered by the bill "should not be licensed under any circumstances," principally on the grounds that they violate human rights.

However, they said, "at very least, embryos with a preponderance of human genes should be assumed to be embryonic human beings and should be treated accordingly," they said.

The bill has been designed as an overhaul of the laws on fertility treatment and would include sections on in vitro fertilization and embryonic research. Britain's 40-year-old abortion laws also would be open to amendment under the terms of the bill.

The government initially proposed to ban the creation of chimeras but changed its mind earlier this year under pressure from the scientific community.

Under the terms of the bill scientists would be allowed to create three different types of human-animal embryos.

The first type – the chimeric embryo – is made by injecting cells from an animal into a human embryo.

The second, the human transgenic embryo, involves injecting animal DNA into a human embryo and the third – a cytoplasmic hybrid – is created by transferring the nuclei of human cells, such as skin cells, into animal eggs from which almost all the genetic material has been removed.

The bill does not allow the creation of "true hybrids" by fusing the egg and sperm of humans and animals and stipulates that human-animal embryos must be destroyed after two weeks.

The bill would also extend the statutory storage period for embryos from five to 10 years. It would allow the screening of embryos for genetic or chromosomal abnormalities that might lead to serious medical conditions or disabilities or miscarriages.

It also would allow doctors to check whether an embryo could provide a suitable tissue match for a sibling suffering from a life-threatening illness.

Under provisions of the bill, fertility clinics would no longer be able to deny treatment to lesbians and single mothers. In certain circumstances, a gay male couple would be able to apply for a parental order in surrogacy cases.

Such provisions were opposed by the bishops in their submission. They said they found offensive the practice of creating an embryo especially to cannibalize its tissues and said that "deliberately to sanction the conception of children who will be deprived of both a genetic and social father is to place the wishes of adults above the human rights of the child."