Complex sentence: The decision, in the early 1970s, to grant UK family planning clinics the ability to prescribe single women the pill was contentious as until then the government had felt that contraception encouraged promiscuity or "free love".
Split into simpler sentences: The decision, in the early 1970s, to grant UK family planning clinics the ability to prescribe single women the pill was contentious. Up until that time, it was felt by the government that contraception encouraged promiscuity or "free love".