Hungarian civic groups under attack by anti-migration Prime Minister Viktor Orban called on the government Monday to withdraw a bill seeking to criminalize their work with asylum-seekers and refugees.

The Hungarian Helsinki Committee and Amnesty International said the legislation, dubbed "Stop Soros" by Orban's government, is designed to intimidate aid workers and human rights advocates by threatening them with up to a year in prison.

The proposal "has no place in a civilized country, in the EU, in a state under the rule of law," Helsinki Committee co-chair Marta Pardavi said outside parliament, calling the threat to individuals working for causes the government opposes a "very powerful turn."

The law, part of right-wing populist Orban's crusade to prevent Hungary from "becoming an immigrant country," would make it a criminal offense punishable by up to a year in prison to promote or facilitate "illegal migration." Debate on the bill is scheduled to start Tuesday in parliament.

Orban's Fidesz party defended the legislation, as well as a proposed constitutional amendment that also is designed to restrict immigration. The prime minister maintains that Hungarian-American billionaire George Soros and the civic groups Soros financially supports are working to bring Muslims from other parts of the world on a large scale, charges they deny.

"The Soros network is protesting 'Stop Soros' and the constitutional amendment because they want to settle migrants in Europe," the party said in a statement Monday. "For us, Hungary is first, and we are not giving our country to anyone."

The Helsinki Committee's Pardavi said that by denying asylum-seekers access to legal aid, the bill aims to keep out of Hungary refugees who file asylum claims at transit zones on the country's southern border with Serbia.

"The criminalization of legal assistance is something that has not happened in Hungary since the 1950s," she said, referencing the period when Hungary was under Soviet domination. "Human rights defenders are not criminals."

The United Nations refugee agency and by the Council of Europe's commissioner for human rights also have criticized the bill since it was introduced last week.

Amnesty International Hungary director Julia Ivan said if the law is approved, Hungarian civil groups would challenge it in the European Court of Human Rights and Hungary's Constitutional Court.