FACTBOX-Human Fertilisation and Embryology Bill

LONDON (Reuters) - MPs continue debating the Human Fertilisation and Embryology bill on Tuesday. Here are some key facts about the bill:

-- The bill updates laws on assisted reproduction treatment and embryo research to take account of scientific developments and social attitudes since the last fertilisation legislation was passed in 1990.

-- The bill does not include any proposal to change abortion laws. But anti-abortion MPs have submitted amendments calling for various reductions in the 24-week limit for terminations, some to as low as 12 weeks.

-- The bill removes the need for doctors to include "the need for a father" when considering the welfare of any child that might be born, before offering fertility treatment. This removes discrimination from lesbian couples or single mothers seeking fertility help.

The Christian Medical Foundation (CMF) says this is an attack on the family.

-- On Monday, MPs voted to allow the creation of four types of human-animal hybrid embryos for the purposes of research, including Cytoplasmic hybrids, created by transferring the nucleus of a human cell into an empty animal cell.

This is the main type of hybrid embryo that scientists want to use -- because of a shortage of donated human eggs -- to create embryonic stem cells to find cures for conditions like Parkinson's and multiple sclerosis.

-- None of the hybrid embryos will be allowed to develop beyond 14 days or be implanted into an animal or human

-- MPs on Monday also voted to allow the screening of embryos to select a "saviour sibling" to help an existing brother or sister suffering a serious disease, most commonly one needing a bone marrow transplant.