Girls as young as 13 are to receive the contraceptive pill without their parents' knowledge in a pilot scheme being introduced on the Isle of Wight.
The scheme, run by the NHS, aims to reduce teenage pregnancies by giving young women counselling on contraception and sexual health as well as a month's supply of the pill.
It has been widely criticised by local church and community groups.
The Reverend Anthony Glaysher, parish priest at St Mary's Catholic Church in Ryde, told the BBC that the scheme "fundamentally attacked the family".
Andrew Turner, Conservative MP for the Isle of Wight, said: "How can adults bring up their children if their children can go into a shop, more or less, and be handed over something which is so significant?
"I will be making my concern clear to the people who run the health service and they've got to understand that many people feel the same."
Ten of the island's 30 pharmacies will be able to provide a month's supply of the pill to a teenager without the need for a prescription.
After that month is up, girls must make an appointment with their GP or sexual health nurse in order to get any additional supplies
Dr Jenifer Smith, director of public health at NHS Isle of Wight, said the scheme would mean that a teenage girl seeking emergency contraception would be given a private consultation.
During this, the pharmacist would discuss the side effects and possible complications of contraception, provide advice on sexually transmitted infections, make a referral to the island's sexual heath service and provide a month's supply of the pill.
She said: "It is not for the health service to moralise on the rights and wrongs of under-age sex but earlier this year we identified a gap in the local arrangements.
"A girl aged 13 to 16 could access emergency hormonal contraception whenever needed but would not be referred to the sexual health service for counselling and a discussion about the longer term effects of their sexual activity such as sexually transmitted infections.
"The main aim is to safeguard vulnerable young people who in some circumstances find it difficult to speak to their parents about these important issues," she added.
Gary Warner, a community pharmacist on the Isle of Wight, said: "The service has been carefully thought through with excellent communications and a 'whole system' approach taken involving GPs, sexual health services, youth services and the island's pharmacists.
"We are confident that it will help protect the young women from unwanted pregnancy but also from sexually transmitted infections by ensuring that they have the confidence and the access to our condom distribution scheme which is offered free of charge through the pharmacies on the island."
Agencies