KANSAS CITY, Mo. — Critics of a new Missouri ban on abortions at or after eight weeks of pregnancy are asking a judge to block the law from taking effect this week.

Attorneys for Planned Parenthood and the American Civil Liberties Union head to court Monday to ask U.S. District Judge Howard Sachs to put the law on hold while their legal challenge against it plays out in court. They face a tight deadline: The law is set to take effect Wednesday.

Planned Parenthood and ACLU lawyers in a court filing wrote that unless Sachs blocks the law, it will severely limit access to abortion and prevent the "vast majority of patients from obtaining the constitutionally protected medical care they seek."

"As a result, some patients will be prevented from obtaining abortion care entirely, and be forced to carry their pregnancies to term against their will_for some, even in the face of significant health risks that nevertheless would not qualify as a 'medical emergency' under the Bans," attorneys wrote.

They added that other patients will seek abortions out of state or "outside the medical system," despite health risks.

The law includes exceptions for medical emergencies, but not for rape or incest. If courts don't uphold the eight-week ban, the bill includes a series of less-restrictive bans ranging from 14 weeks up to 20 weeks. The bill also bans abortions based solely on race, sex or a diagnosis indicating the potential for Down syndrome.

Attorneys for the state argue that courts have allowed limits on abortions based on the gestational age of the fetus, although similar abortion restrictions in North Dakota and Iowa have been struck down by judges. In court documents, they told the judge that the state's goal is "protecting fetal life" as well as protecting women.

Federal law allows states to prohibit abortions after fetuses are viable outside the womb, which can be from 24 to 28 weeks.

Missouri's bill also includes an outright ban on abortions except in cases of medical emergencies, but that would take effect only if the landmark 1973 U.S. Supreme Court's Roe v. Wade ruling that legalized abortion nationwide is overturned.

Missouri already has some of the nation's most restrictive abortion regulations. Just one clinic in the state performs abortions.