“We do not want to form part of a law which prostitutes Malta’s identity and its citizenship,” Mario de Marco, a vocal member of the opposition, said during the debate.

The opposition took the program to the European Parliament in an effort to block it. While the Parliament condemned the program, it could do little else, because citizenship is controlled by national governments.

To placate the Parliament and the opposition, the government raised the bar for citizenship. Strict due diligence standards were set to weed out money launderers and criminals. It also raised the cost and adopted a residency requirement. In addition to the €650,000 fee to the government, applicants must now invest €150,000 in government bonds, buy property for at least €350,000 or rent a place for at least €16,000 a year — all of which must be held for at least five years.

“This is not ‘tick the box,’” said Mr. Cardona, the chief of the program.

Mr. Hyzler, the lawyer, and others note that the newcomers are establishing real links to Malta. They are setting up bank accounts and buying health insurance, both of which are required. They are also joining country clubs and donating to local charities, which is encouraged.

“Clients genuinely want to do more than just make the investment,” said Mark Stannard, managing director of the Maltese office of Henley & Partners, a residence and citizenship planning firm. He said a Saudi national with a Lebanese passport who had applied for Maltese citizenship had recently returned with a delegation of 12 to consider setting up businesses in aviation, life sciences and real estate.

My. Hyzler said some of his Chinese clients wanted to invest more than the €150,000 in government bonds and were weighing establishing businesses.