Mr Hacking then responded: “So it’s a criminal offence to pray, according to the court order, it’s a criminal offence to pray outside of a place where children are being killed?” The officer then stated:  “I believe that I’ve given you the answer.”

Officers then failed to caution MR Hacking before his arrest.

A Marie Stopes UK spokesperson said: “Nobody should face harassment when accessing a legal, confidential health service, and the Safe Zone around the Marie Stopes West London clinic rightly prohibits a range of activities within 100metres, including prayer.  

“It is disappointing to see wilful non-compliance with the PSPO fail to result in prosecution, however, the Ealing Safe Zone remains a vital measure to ensure anyone accessing abortion services has consistent and necessary protection from intimidation and harassment, and we continue to call for similar protections to be introduced across the UK.”

A Metropolitan Police spokesman said: “A 29-year-old man was charged in August 2019 with failing to comply with a public space protection order following an incident in Ealing. The matter was subsequently discontinued.”

A CPS spokeswoman said: “We have a duty to keep cases under continuous review and, following a further assessment, we concluded there was insufficient evidence to provide a realistic prospect of conviction.”