In 1983 the Attorney General ruled that emergency contraception is not a form of abortion because there is no established pregnancy to terminate. It is medical and legal opinion that pregnancy begins when an egg is implanted in the womb and emergency contraception acts before this stage is reached.
This was confirmed in 2002 during the course of a judicial review of the pharmacy provision of emergency contraception sought by the Society for the Protection of the Unborn Child.
Justice Munby, confirming the statement of the Attorney General, said "the word miscarriage today means the termination of an established pregnancy, and there is no established pregnancy prior to implantation… It follows that since the morning after pill (sic) is used before the process of implantation has begun, and because it cannot make an implanted egg de-implant, the morning after pill (sic) cannot as a matter of law bring about a "miscarriage"."