An estimated 10,372,100 lives have been lost since the Abortion Act came into effect on this day in 1968.
In 2021, the last full year for which abortion statistics are available, more than one baby was being aborted every two and a half minutes across England, Wales and Scotland.
That year saw record high numbers of abortions, with 214,869 in England and Wales, and 16,596 in Scotland.
Right to Life UK attributed the increase to the introduction of the pills by post service that allows women to take both abortion pills at home up to the first 10 weeks.
A spokesperson for Right To Life UK, Catherine Robinson said: "The UK's abortion law is failing both women and unborn babies. It is a national tragedy that 10,372,100 lives have been lost since the 1967 Abortion Act came into effect, each one a unique and valuable human being who was denied the right to life.
"Every one of these abortions represents a collective failure of our society to protect the lives of babies in the womb and a failure to offer full support to women with unplanned pregnancies.
"While we may pause to commemorate this tragedy, this day also serves as a call to action for people around the country to renew their efforts to do everything they can to help ensure more lives are saved from abortion in the future."
The anniversary of the Abortion Act is being remembered this year as MPs launch a fresh attempt to radically change the UK's abortion laws.
An amendment tabled to the Criminal Justice Bill by Labour MP Stella Creasy wants to remove the possibility of custodial sentences for abortions after 24 weeks. If passed, Right to Life said it would lead to more late-term abortions.
Ms Robinson urged people to contact their MPs to ask them to ensure that protections for unborn babies and mothers are strengthened.
"By being proactive and taking action, every single one of us can be part of building a pro-life nation where we protect and defend the right to life of every human being from conception to natural death," she said.
