SUPPORTERS of delivery driver Peggy Young rallied outside the Supreme Court in Washington today as her hearing against United Parcel Service started.

Ms Young has been trudging through the US court system for the last seven years, in pursuit of a claim that UPS discriminated during her pregnancy in 2006 by refusing her a temporary assignment to avoid lifting heavy packages.

The case has the potential to affect many thousands of US women who continue to work throughout their pregnancies.

Ms Young applied for light duties when she became pregnant but UPS refused when she presented a doctor's note recommending she not lift packages heavier than 20 pounds.

Although she dealt almost exclusively with overnight letters, UPS insisted its drivers must be able to lift packages weighing up to 70 lbs.

The court is now weighing whether the refusal violated the US Pregnancy Discrimination Act.

Ms Young claims she should have been offered light duty, citing the precedent of other UPS workers, including those injured on the job or with a condition covered by the Americans With Disabilities Act.

More than 120 Democrats are now backing legislation to change federal law to accommodate pregnant women.

Senator Bob Casey said the Bill was modelled on the disabilities law.

"It would make sure that pregnant workers have the same measure of protection," Mr Casey told supporters outside the court. The US Equal Employment Opportunity Commission has now updated guidance to employers to make clear that they should accommodate people in Ms Young's situation.