The shadow business secretary, a frontrunner in the race, said it was her personal view, not a policy position, while a spokesman clarified she “unequivocally supports a woman’s right to choose”.
Ms Long-Bailey’s team was re-iterating her stance on Thursday after the comments made to representatives of Salford’s Catholic cathedral during the general election campaign surfaced.
The British Pregnancy Advisory Service (BPAS) was critical of the remarks, and invited her to a clinic in Manchester to “better understand” the support they provide.
The Salford and Eccles MP, who is Catholic, was asked if she would remove “discrimination on grounds of disability” in abortion law.
“It is currently legal to terminate a pregnancy up to full-term on the grounds of disability while the upper limit is 24 weeks if there is no disability,” she replied.
“I personally do not agree with this position and agree with the words of the Disability Rights Commission that ‘the context in which parents choose whether to have a child should be one in which disability and non-disability are valued equally’.”
A spokesman for Ms Long-Bailey criticised the Red Roar website which first reported on the comments, saying the “fake news peddlers” were trying to “propagate a misleading narrative”.
“Rebecca unequivocally supports a woman’s right to choose and has only ever voted in favour of extending the right to abortion, such as in Northern Ireland,” he added.
“Rebecca’s response to the deanery of Salford clarified the existing law and current Labour policy, stating that abortion procedures should be properly regulated, and that women’s reproductive rights and the decriminalisation of abortion should be maintained.”
Her reply was a “reflection” on her agreement with the commission “rather than her view on policy”, he added.
BPAS spokeswoman Katherine O’Brien said: “Many serious fetal anomalies are not diagnosed until the second trimester or beyond.
“Removing the ability for women in these extremely challenging circumstances to end a much-wanted pregnancy would deny them the time and space they need for further tests and counselling before they make their decision.
“It would force women to bring a child into the world when they do not think it is right to do so, and compel other women to give birth to a baby that they know will shortly die. These are extremely difficult decisions for women and their partners to make, and they deserve empathy and support.”
She stressed only 0.1% of all terminations in England and Wales in 2018 took place after the 24-week mark and were for “heartbreaking reasons”.
“There is no contradiction between working to create a more equal society for those with a disability and supporting women’s abilities to make the decisions that are right for them and their family in these desperate circumstances,” she continued.
“Any suggestion that women who end a pregnancy in these situations do not value the lives of disabled people is deeply offensive.
“Aside from the comments regarding abortions for serious fetal anomaly, it appears that Rebecca Long-Bailey may not fully understand that there are a myriad of reasons why one in three women in this country will have a termination in their lifetimes.
“We would be pleased to invite Rebecca Long-Bailey to visit our clinic in Manchester so that she can better understand the support we provide to her constituents and the reasons why they need to access abortion services.”
Meanwhile, Ms Long-Bailey received a boost to her campaign on Thursday when she won the endorsement of the Momentum group.
The campaigners vowed to run “hundreds” of phone banks across the country and encourage supporters to use apps to make “hundreds of thousands of calls” to members in support of Ms Long-Bailey.