WARSAW, JUNE 4 -- Pope John Paul II waded deeper into Poland's bitter dispute over abortion today, comparing it to the Nazi Holocaust and declaring that Polish lawmakers have no right to keep it legal.

"What human institution, what parliament, has the right to legalize the killing of an innocent and defenseless human being?" the pope shouted in his homily before an estimated 250,000 worshipers at an outdoor Mass in Radom. "What parliament has the right to say 'you are free to kill,' or even 'killing is in order?' "

The pontiff's remarks, coming on the heels of an emotional anti-abortion plea before 150,000 people in Kielce Monday, are certain to divide this overwhelmingly Catholic country even further on the issue, and on other attempts by the Poland's powerful Catholic Church hierarchy to set government social policy.

Last month, the Parliament, concerned by evidence of a growing anticlerical backlash around the country, postponed action on a church-supported bill to ban abortion -- available on demand here since 1956 -- and to jail those who perform them. The bill's sponsors have been counting on the pope's visit to restore their legislative momentum, and he has not disappointed them.

On his first visit to his native land since the fall of the Communist regime in 1989, the pope has toured cities, towns and rural areas throughout eastern Poland, warning of the dangers of a godless society and imploring his countrymen to restore Catholic morality to a central place in their new democracy.

In contrast to the sometimes cryptic homilies the pontiff delivered on three previous pilgrimages here -- when the church walked arm in arm with the Solidarity movement to oppose the Communist government -- the pope this week has spoken bluntly, urgently and angrily.

Today, he recalled this century's two world wars and the Nazi Holocaust, in which more than 6 million Jews, Poles, Gypsies and others were put to death, as "a time when vast areas of our continent became graves of innocent people."

Now, the pope said, "the cemetery of the victims of human cruelty in our century is extended to include yet another vast cemetery, that of the unborn child, of the defenseless whose faces even their own mothers had not seen before accepting, or being pressured into accepting, that their lives be taken away from them before their birth."

About 600,000 abortions are performed in Poland each year, a rate roughly equal to the number of live births. The high abortion rate is widely attributed to the scarcity of inexpensive contraceptives here and to economic hardships that discourage large families.

In his address today, the pope aknowledged some of the social and economic difficulties that press women to have abortions and urged special consideration of their plight. "We must step up our social concern," he said, "not only about the unborn child, but also about his parents -- his mother first and foremost -- if the arrival of her child has pitted her against troubles and worries with which she seems unable to cope alone."