A senior Tory has urged MPs to stop treating ­people with Down’s syndrome as “second-class citizens” by allowing foetuses with the condition to be aborted up to birth.

Former Cabinet minister Liam Fox has written to colleagues saying the current laws are “inconsistent with our disability and equality legislation”.

The time limit to terminate a pregnancy is 24 weeks in most cases but if a foetus is thought to have Down’s syndrome then ­abortion is available up to 40 weeks.

Dr Fox has tabled an amendment to the Government’s Criminal Justice Bill, currently making its way through Parliament, which would end this exception.

In the letter to MPs, the former Defence Secretary said: “The abortion time limits should be equalised as another step along the road to ensuring full equality for people with Down’s syndrome with the rest of society.”

His proposal has cross-party backing and the amendment has been signed by Labour MP Dame Meg Hillier, former Liberal Democrat leader Tim Farron and the DUP’s Ian Paisley, as well as a number of Tory MPs such as former party leader Sir Iain Duncan Smith and former Brexit Secretary Sir David Davis. It would make no change to the law governing abortion in other cases.

There were 859 abortions involving a baby diagnosed with Down’s syndrome in 2021. A legal challenge to the current rules by ­campaigner Heidi Crowter, who has the ­condition, was rejected by the Court of Appeal in 2022 when judges ruled they do not discriminate against living people.

Campaign group Don’t Screen Us Out is backing Dr Fox’s proposal. Spokesperson Lynn Murray, mother of a daughter with the condition, said the current legislation “sends a message that people with Down’s syndrome are less worthy of life and protection than others”.

She added: “Very few people are aware of this discriminatory part of our law that ­singles out babies with disabilities including Down’s syndrome allowing them to be screened out by abortion up to birth.”

If the amendment is put to a vote then it is likely to be opposed by MPs who fear any new restrictions are the start of a “slippery slope” that could limit access to abortion.

Separately, a cross-party group including former Labour deputy leader Harriet Harman and Conservative MP Dehenna Davison are backing an amendment to the Criminal Justice Bill that would prevent any woman being prosecuted for terminating a pregnancy outside the law, such as after the 24-week limit or without obtaining the approval of doctors.

Another amendment, backed by former Equalities Minister Dame Maria Miller, would remove parental responsibility from any man convicted of a serious sexual offence involving a child.