The Family Planning Association (fpa) has launched a campaign to protect the current 24-week time limit for abortion.
The limit was reduced from 28 weeks in 1990, but anti-abortion groups and some MPs have attacked the limit and are seeking to deny women access to the procedure.
Julie Bentley, chief executive of the fpa, commented: "For the first time in 18 years, the issue of abortion is going to be scrutinised through a government bill in parliament.
"The most vulnerable women needing a late abortion are the ones who stand to lose if the time limit is cut.
"In line with all the current ethical, medical and scientific thinking fpa, as proud advocates of women's right to choose, will be fighting hard to protect the time limit from any changes."
The association's website features case studies and information on abortion and 1,000 people have so far signed an online petition in favour of maintaining the current 24-week time limit.