A peer collapsed in the House of Lords last night minutes after delivering a speech on the human fertilisation and embryology bill.
The Labour peer Lord Brennan collapsed in the chamber during the second reading of the controversial bill.
Fellow Labour peer Lord Darzi performed heart massage on the 65-year-old.
Lord Darzi is practicing a heart surgeon who entered politics under Gordon Brown's "government of all the talents".
Ambulance crews treated Lord Brennan in the chamber before he was admitted to Guy's and St Thomas' hospital at 8:43 pm. A spokesperson said last night his condition was stable.
Lord Brennan, a committed Roman Catholic, is the Home Office's independent assessor on miscarriages of justice.
Following his collapse, the debate on the human fertilisation and embryology bill was adjourned until tomorrow.
The bill will make it easier for lesbian and gay couples and single women to become parents. It downgrades the role of fathers, removing the need for doctors to consider the "need for a father" when approving IVF treatment.
It will also allow the development of 'saviour siblings' to treat genetic conditions as well as furthering embryology research, including the limited use of hybrid embryos.
Supporting the bill, Lord Darzi said it would ensure the regulations surrounding assisted reproduction are effective and reflect modern society. Despite fierce opposition to the bill, he insisted technology and attitudes had moved on and legislation needed to reflect this.
Lib Dem peer Baroness Shirley Williams argued removing the need for a father risked creating more dysfunctional families.
The bill is likely to prove more contentious when it enters the House of Commons, where several MPs are expected to use it try and amend abortion law.