New Department of Health rules say midwives and nurses may administer the drugs to terminate pregnancies.
Ann Furedi, chief executive of the biggest abortion provider, British Pregnancy Advisory Service, welcomed the changes, saying: "We think nurses are the best people to deliver early abortions. Abortions should be carried out by people who are clinically qualified to do it, including nurses."
But the move has been condemned by MPs and anti-abortion campaigners.
Crossbench peer Lord Alton said: "It is particularly perverse that midwives, who do the beautiful work of helping babies into the world, will now be called upon to end the lives of children they might otherwise work to save."
Tory MP Fiona Bruce said: "This is a clear liberalisation of abortion law which people do not want."
Under previous guidelines, midwives and nurses could undertake 'certain actions' in helping to terminate unwanted pregnancies.
But the new rules go much further and state clearly that a 'nurse or midwife may administer the drugs used for medical abortions'.
The move follows pressure from the Royal College of Nursing and abortion providers, who believe the law should be changed to allow nurses full control of abortion induced by drugs or some other techniques.