By Adam Easton
BBC News, Warsaw
The Polish parliament has approved a bill designed to remove people who collaborated with the communist secret services from public life.
New buildings stand next to reminders of Poland's past
The bill could lead to the dismissal of hundreds of thousands of people working in business, the media and government.
Unlike other former Soviet-bloc countries, Poland has never carried out a purge of people who collaborated with the former communist regime.
The legislation will now go to Poland's upper house and president for approval.
For 17 years, Poland has struggled to come to terms with the legacy of its communist past.
Until now, collaboration with the former communist secret police was not a bar to public office, as long as you signed a declaration admitting it.
Exemption for priests
This new law will allow employers to use evidence of collaboration as grounds for dismissal.
Accusations forced the resignation of Finance Minister Zyta Gilowska
People whose past will be coming under scrutiny will include public officials, company bosses, journalists and teachers.
The names of informers and parts of their files can be published on the Internet.
While most Poles would like to see some form of resolution to the problem, the new law is controversial.
Many secret police files are missing or have been tampered with.
Even high-profile careers have been wrecked by suspicion of collaboration.
The well-respected former finance minister, Zyta Gilowska, was recently sacked after she was accused of informing - claims she strongly denies.
And the bill does not include the clergy even though an estimated one in ten Polish priests collaborated with the communist regime.