Conservative members of the European Parliament on Wednesday blocked moves to extend maternity leave to a minimum of 20 weeks across the EU.
The conservatives argued that given 89 amendments were needed, any vote "would not be clear enough." It means the whole process will start again from scratch once a new parliament is formed after next month's elections.
"The European right has shown its true colours in betraying the well-being of millions of women who want a better balance between their family life and work," said Martin Schulz, head of the Socialist bloc in the assembly.
Under current European law, dating from 1992, employers must offer 14 consecutive weeks of maternity leave. The new package would extend that by six weeks, including six weeks fully paid.
Men would also be entitled to two weeks' paternity leave.
"The EU wants to modernise legislation that is 17 years old and really out of date," said Socialist Portuguese lawmaker Edite Estela, the plan's parliamentary rapporteur.
"But when there is a right wing majority in the (EU) council of ministers, in the (European) Commission and in the European Parliament, it is extremely difficult to change mindsets and move forward on women's issues."
However the package did not have the support of all European Union nations, as the 20-week plan would require some countries to make significant changes to their national legislation.
Germany led opposition to the move, claiming it would make it more financially risky for employers to hire young women who might fall pregnant and hurt their chances of finding a job.