The BBC's for and against cases
BARONESS RUTH DEECH Ex-head of the Human Fertilisation and Embryology Authority
"English law provides very clearly the democratic principle and the principle of autonomy.
"At every stage throughout IVF, the consent of both the man and the woman must be preset and must not be withdrawn.
"It embodies equality between the sexes and consent which is deeply embedded in medical law, especially procreative law."
Baroness Deech said men - like women - should have the right to say no.
The principle of equality is very important
"Women have fought a long hard battle along the lines of no means no.
"And the danger with this advanced science of IVF is that men are gradually being cast aside, whether its cloning or anything else.
"They are being reduced to a sort of genetic blob and, having done their duty in the laboratory, are no longer necessary.
"It's a great shame."
She added: "It's a tragic case, and of course it could have been avoided.
"If Natallie Evans had not had her embryos produced, but had frozen her eggs or even a slice of ovarian tissue, thereby keeping control.
"But the principle of equality is very important.
"I do not think it is the same as a natural pregnancy .
She said there were situations where a woman could make a decision which would end a man's chance of parenthood - say if a man had cancer treatment after his partner became pregnant, and she decided to have an abortion.
"It's very sad, but these things happen when people don't continue with the emotions they once felt towards each other."
JOHN HARRIS
Professor of bioethics at Manchester University School of Law
"These two people made a decision to try to have children.
"Howard Johnston gave his considered, fully informed, consent to fertilisation of the eggs, the creation of the embryos and the 'procreative enterprise'.
"I do not see why he should now be permitted to break this contract and withdraw unilaterally from the procreative enterprise with such disastrous consequences for Natallie.
Normal sexual intercourse is an appropriate model
"This is her last chance to have her own genetic children.
"Normal sexual intercourse is an appropriate model here.
"The man consents to sexual intercourse. If the couple are trying to have children, he consents to the attempt to have children.
"If his partner becomes pregnant, he has no further say in the continuation of that pregnancy and the birth of that child.
"It would be disastrous if the basis of the EU decision was anything to do with the rights of the embryo.
"It has to look objectively at what the two people have to lose - and Natallie Evans has much more to lose than Howard Johnston."