Kerry Mellor, 75, received his first fine in April for breaching the zone about a month after the laws banning protest were introduced.

But police withdrew that fine last month.

A delegate of the chief police officer told Mr Mellor police had decided to withdraw the fine notice due to "ambiguity" around the "boundaries of what comprises a 'protected area'".

Days after the fine was withdrawn, the ACT government announced it had expanded the exclusion zone, to include Rudd Street, West Row, the alleyway of Odgers Lane, and surrounding roads, footpaths, gutters, outdoor areas, and underneath a "building's facade".

But last Friday Mr Mellor received a second fine.

He said that when he and other pro-life supporters went to the Moore Street clinic at 8am, there were already six police officers there.

The rest of his group dispersed, he said, but he remained in place outside PJ O'Reilly pub and was again fined $750.

"The moment that I produced my rosary and made a sign of the cross, they were on to me right away," he said.

Mr Mellor argues that praying does not amount to either protest or prohibited behaviour under the exclusion zone laws.

He said he intended to challenge the fine in court.