The local authority in Bournemouth has charged a retired medical scientist who held a sign near an abortion clinic saying "here to talk, if you want to".
Bournemouth council accuses Livia Tossici-Bolt of breaching a buffer zone which criminalises expressions of approval or disapproval of abortion within 150m of the clinic.
The Alliance Defending Freedom UK (ADF), which is supporting her, said that several individuals approached Tossici-Bolt to discuss their circumstances while she was holding the sign.
She has been charged after she refused to pay a fixed penalty notice issued by the council. She denies breaching the terms of the buffer zone and argues that the right to consensual conversations is protected under Article 10 of the Human Rights Act.
The 62 year old is awaiting a trial date at Poole Magistrates' Court. She said it should not be a crime to offer help.
"We all condemn harassment. But 'buffer zones' are going so far even to criminalise activities which are peaceful and helpful," she said.
"For several years now, I have been offering a helping hand to women who would like to consider other options to abortion, and pointing them to options where they can receive financial and practical support, if that's what they would like.
"There's nothing wrong with offering help. There's nothing wrong with two adults engaging in a consensual conversation on the street. I shouldn't be treated like a criminal just for this."
Jeremiah Igunnubole, Legal Counsel for ADF UK, blamed "vaguely-written" buffer zone measures, which have seen some pro-life volunteers arrested for praying silently in their heads.
"The principle of freedom of thought and speech must be defended both within and outside 'buffer zones'," he said.
"The Home Office have sought to keep our country in line with international law by protecting freedom of thought and of consensual conversation in the draft buffer zone guidance. It is vital, for the preservation of democracy, that this stands."
The local council recently apologised to Tossici-Bolt for causing her to feel "distressed and harassed" on a separate occasion when officers wrongfully tried to move her from a public street for holding a sign that said "Pregnant? Need help?" along with the number for a helpline.
She was accused of being within the buffer zone but the council later conceded that she was outside the boundary.
Igunnubole said her treatment had exposed the "reality of the slippery slope of censorship".
"If the state is allowed to criminalise the mere holding of pro-life viewpoints within certain public spaces, on what basis can we object to criminalisation in all public spaces?" he said.
"The purported blanket bans on prayer and consensual conversations were never about the prevention of harassment and intimidation – after all, in the UK, not a single pro-life vigil volunteer has been convicted for harassment and intimidation in over 40 years of pro-life presence near abortion facilities."
