Three leading judges dismissed an appeal against an earlier ruling that restrictions imposed by Ealing Council in west London on protests, including prayer, outside a Marie Stopes clinic (below) were "justified".
The authority was the first to create a buffer zone in April 2018 following demonstrations.
It imposed the public spaces protection order (PSPO) following reports of "intimidation, harassment and distress" for women using the facility in Mattock Lane, Ealing.
Following the ruling, family planning organisations urged the Government to consider national legislation to create buffer zones outside every abortion clinic in the country.
Marie Stopes UK's managing director Richard Bentley said: "From the day it was introduced this PSPO has protected the wellbeing of everyone coming to our west London centre.
"But ultimately, a PSPO is not an adequate response to what is a national problem, leaving most clinics across the country defenceless.
"It is time for the UK Government to end the postcode lottery of harassment and legislate for safe access zones outside all registered abortion care providers in the UK."
Clare Murphy, director of external affairs at the British Pregnancy Advisory Service said: "We welcome the Court of Appeal's decision.
"However, the harassment and intimidation of women and abortion clinic staff remains a national problem in need of a national solution."
Ms Murphy said that, since then Home Secretary Sajid Javid rejected calls for national legislation in September 2018, there had been protests outside 32 clinics and hospitals.
She also said it was "unrealistic" to expect cash-strapped councils to dedicate time and resources to pursuing PSPOs.
She added: "Today's judgment confirms that buffer zones are legal, proportionate, and necessary.
"We urge the new Home Secretary Priti Patel to listen to the voices of women, medical bodies, and women's rights organisations, and look again at the case for national legislation."
Labour leader Jeremy Corbyn also welcomed the ruling, tweeting: "Good news. A woman's right to choose, free from intimidation or harassment, must be protected."
Alina Dulgheriu (below) and Andrea Orthova, who regularly attend a vigil run by Christian organisation the Good Counsel Network (GCN), mounted a legal challenge at the Court of Appeal in a bid to overturn the ban on protests directly outside the clinic.
It was argued on their behalf that the ban interferes with their rights under the European Convention on Human Rights to freedom of expression, freedom of religion or belief and freedom of assembly and association.
They also said the council was wrong to use a PSPO because the orders were designed to protect local residents from anti-social behaviour, and clinic users were "one-off or occasional" visitors to the area.
But their case was rejected on Wednesday by Master of the Rolls Sir Terence Etherton, Lady Justice King and Lady Justice Nicola Davies - who upheld an earlier decision in favour of Ealing by the High Court.
Ms Dulgheriu said she now intends to take her fight against the buffer zone to the Supreme Court.
In a statement after the ruling, she said: "My little girl is here today because of the real practical and emotional support that I was given by a group outside a Marie Stopes centre, and I am going to appeal this decision to ensure that women in Ealing and all across the country do not have this vital support option removed.
"I will continue to stand up for the women whose voices have been sidelined throughout this process and for women who need life-saving support today but cannot get it."
She added: "I refuse to accept that women should be denied the opportunity to receive help where they want to keep their child."
When dismissing the women's case against the PSPO at the High Court in July 2018, Mr Justice Turner said there was "substantial evidence" from clinic users that their privacy was being "very seriously invaded at a time and place when they were most vulnerable and sensitive to uninvited attention".
He also said his ruling did not give the "green light" to local authorities to impose PSPOs around all abortion clinics and each case must be decided on its own facts.
Announcing their decision on Wednesday, the appeal judges said that, for a number of years, members of the GCN had congregated immediately outside the Marie Stopes UK West London centre, usually on a daily basis.
In 2015, a pro-choice group began to hold counter-protests, also immediately outside the centre, which "generated an atmosphere of tension".
After failed attempts to find a compromise between the two groups, Ealing consulted on whether to make a PSPO banning protests in the area.
The judges ruled that "given the established persisting impact upon the quality of life on those visiting the centre as a consequence of the activities of the protest groups, a PSPO was necessary to strike a fair balance between protecting the rights of the service users on the one hand and the protesters on the other".
They said the High Court judge was entitled to have determined that the creation of a "safe zone", which the protesters could not enter, and the provision of a designated area some way off - in which limited protest could take place - was a "proportionate response".
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