MOSCOW — Russian authorities refused to register a new liberal opposition party on Wednesday, frustrating efforts by several prominent Kremlin critics to run in parliamentary elections scheduled for December.
The decision seemed, at the least, inconsistent with recent calls by President Dmitri A. Medvedev for more political diversity in Russia’s parliament, which is currently dominated by a single party, United Russia.
But it was not a surprise to the creators of the new party, called the People’s Freedom Party, who over the years have been squeezed out of a political system monopolized by Mr. Medvedev’s predecessor, Vladimir V. Putin, who is now prime minister and United Russia’s leader.
“We are denied our political rights,” said Vladimir A. Ryzhkov, one of the party’s leaders. “We are not allowed to participate in elections. This is illegal.”
In over a decade in power, Mr. Putin has altered Russia’s political system in a way that has disenfranchised smaller parties. He raised the percentage of votes parties must win to enter parliament, and banned individual candidates from running without party affiliation.
The restrictions cost Mr. Ryzhkov his seat in parliament in 2007 and forced his old party to disband. Other leaders of the new party, including Boris Y. Nemtsov, a deputy prime minister in the 1990s, and Mikhail M. Kasyanov, a former prime minister under Mr. Putin, have been similarly affected.
In an interview published Monday in the Financial Times, Mr. Medvedev said that Russia would benefit from easing some of these restrictions, but called for doing so gradually.
“I would like the whole of the political spectrum to be represented in our parliament,” he said. “I have taken steps in this direction when possible, but I think nevertheless that these steps should not contradict the general trend of development.
Mr. Medvedev’s first term as president ends next year, and it is still unclear whether he or Mr. Putin will run in the presidential election next March. The leaders have said they will decide which of them will run.
Mr. Ryzhkov said the decision to deny his party registration indicated who, in fact, was really in charge.
“Medvedev is an empty chatterbox. His words mean nothing,” he said. “Putin decides everything.”
In reaching its decision, the Justice Ministry cited what it called several technical violations including a failure to adhere to a rotating leadership structure required by law. It also said in a statement that some of the 45,000 signatures required to show support for the party were provided by under-aged or illegally registered individuals. Some signatories, the ministry said, were dead.
Such technicalities are frequently used to deny opposition groups the chance to participate in elections here, independent election monitors say. While party leaders said some mistakes could have been made, none should have warranted a denial.
The Justice Ministry said it was possible to resubmit corrected application materials, but Mr. Ryzhkov said the party would boycott the upcoming elections and plan protests instead.