The government has been accused of pushing ahead with plans to strip abortion providers of their role in counselling women despite an amendment on the issue suffering a heavy defeat in the Commons last year.
Shadow public health minister Diane Abbott said she had walked out of a new cross-party abortion group set up by the government to look at the issue of counselling following the defeat.
She accused the government of "ploughing ahead" with the controversial abortion changes, saying the new group was a "front" for pushing through the plans which were "unwanted, undemocratic and unsubstantiated with evidence".
The British Pregnancy Advisory Service (BPAS) also expressed dismay at what it sees as aims to implement the changes anyway.
In September MPs have voted against proposals to change the law governing advice given to women seeking abortion.
Conservative MP Nadine Dorries had tabled an amendment to the Health and Social Care Bill that would have banned organisations that carry out abortions, such as Marie Stopes, from offering counselling.
Dorries has argued that because they receive money for carrying out terminations, the organisations have a vested interest.
Critics of the Mid Bedfordshire MPs amendment warned that it would open up the way for religious groups with an anti-abortion agenda to get involved.
MPs were given a "free vote" on the amendment on Wednesday. They voted against change by 118 to 368 - a majority of 250 votes.
But despite the defeat Dorries claimed victory. She told the BBC that a "massive spotlight" had been shone on the abortion "industry".
"It has been a most tremendous success. We've lost the battle but we've won the war," she said.
Public health minister Anne Milton said just before the vote that the government would try to implement the spirit of Dorries' proposal without the need for legislation.
She said: "The government supports the spirit of the amendments, and we intend to present proposals for regulations after consultation."
The cross-party group has now been meeting to discuss three proposals, which could include stripping providers of their current role, to form part of this consultation.
The cross-party group includes Milton and Dorries.
Abbott, who voted against the amendment in the Commons, said the government still intended to strip providers of their roles.
In a letter to Milton, she said: "I entered into the meetings in good faith.
"I was genuinely interested in improving the quality of counselling available to women.
"But I now believe the 'consultation' will be a front for driving through the anti-choice lobbyists' preferred option without legislation or a debate on the floor of the House."
She added: "There is no doubt which option the government wants to drive through. There will be no legislation or debate in Parliament.
"These changes are unwanted, undemocratic and unsubstantiated with evidence.
"I think women and families across the country will be as horrified as I am by the way the government is trying to turn the clocks back.
"The talks that have taken place have been little more than window dressing for what is an aggressive, anti-choice campaign and I am walking away from them.
"It's a group of 'Tea Party Tories' who are determined to plough ahead, despite these policies being decisively rejected by Parliament, by the medical profession and also by the British public.
"I think we need to fight back against these policies.
"Women in this country want to have choice over their fertility and that is a basic human right."
Dorries has claimed the real reason Abbott was leaving the committee "could be because she hasn't got a clue what is going on!"
Critics of the existing system say clinics currently offer biased information, because their funding from the Government depends on the number of terminations they carry out.
Pro-life campaigners believe introducing independent counselling could reduce the number of abortions.
BPAS and others say changing the way counselling is provided would be damaging to women.