Pro-choice supporters are to protest against anti-abortion activists outside a London clinic run by Britain's largest abortion provider later this month.

The counter-protest at the Bedford Square clinic of the British Pregnancy Advisory Service (BPAS) on 30 March will be the first of its kind in the UK.

It is timed to coincide with a planned prayer vigil outside the clinic which will be attended by the Roman Catholic bishop of Westminster, Alan Hopes.

The clinic is the same one where BPAS said earlier this month that women were being filmed arriving and leaving.

It has also been targeted by activists from the 40 Days for Life campaign, which is affiliated to a US anti-abortion network.

BPAS, whose website was also the target of a cyberattack by a hacker days before, has said it is facing "a new era" in terms of the actions anti-abortion protesters are prepared to take.

The 40 Days for Life campaign, which distanced itself from the man who was filming outside the clinic, has called for "a big turnout" for the vigil on 30 March, which it said would be led by Hopes.

The bishop last year joined another anti-abortion organisation, Helpers of God's Precious Infants, to lead a vigil at a BPAS clinic in Twickenham.

Abortion providers including BPAS and Marie Stopes have been reluctant in the past to endorse counter-demonstrations outside their clinics.

However, pro-choice activists say they decided to mount the counter-demonstration because the BPAS clinic is to be closed.

The development is likely to cause concern that Britain's abortion debate is beginning to resemble the very polarised terrain of the US, where medical staff at abortion clinics have been killed by anti-abortion extremists and heated confrontations between both sides have become a regular occurrence.

Darinka Aleksic of Abortion Rights, the national pro-choice campaign, said: "We strongly oppose the tactics of anti-choice groups such as 40 Days for Life.

"While they have a right to express their views, picketing abortion clinics, handing out grossly inaccurate information and filming people entering the premises does not help their cause.

"Whatever their views on abortion, most people will agree that intimidating and distressing individual women trying to access a legal medical service is unacceptable.

"In America women are routinely harassed and abused outside clinics and abortion providers fear for their lives. Now US anti-choice groups are setting up shop over here.

"We need to send a very clear message that we will not tolerate that sort of activity in the UK."