Legislation banning the reproductive cloning of human beings was introduced in parliament on Monday.

The government is rushing through the emergency legislation following a High Court ruling on November 15 that the 1990 Human Fertilisation and Embryology Act does not make human cloning illegal.

The new Human Reproductive Cloning Bill received its second reading in the Lords on Monday and is likely to finish all stages in the Commons by the end of this week.

The government action also comes just one day after a US company announced it had cloned a human embryo.

Earlier this month High Court judges backed arguments by the anti-abortion Pro-Life Alliance that cloned embryos are not covered by the 1990 Act because they do not meet the definition of an embryo - the fertilisation of an egg with a sperm.

The ruling means that in theory there is currently no law preventing someone attempting to create a human clone, though they would be likely to face professional sanctions and medical malpractice lawsuits

As a result of the ruling, the Department of Health has proposed a new law making it a criminal offence "to place in a woman a human embryo which has been created by a method other than by fertilisation". But critics say this still leaves a number of legal loopholes.

The Pro-Life Alliance has said it won't stop human cloned embryos being placed in animals, and because there is no definition of fertilisation or when an embryo becomes a foetus the law might not cover the nurturing of a cloned embryo in a laboratory to the point where it is no longer an "embryo" before being implanted into a woman.

The Alliance supports the banning of any cloned human embryo, but the government and many scientists believe "therapeutic cloning" offers significant potential for developing health treatments. The new legislation will allow stem cell and other research using embryos created by fertilisation to continue.

The government is also appealing against the High Court ruling, hoping to return regulation of "therapeutic cloning" to the Human Fertilisation and Embryology Authority.