The Russian Federation, the biggest Soviet republic, has launched a radical economic reform plan that could stir fresh disputes with the Kremlin.

Russian Prime Minister Ivan Silayev said the "500-day" plan would begin as scheduled Thursday, but deputies in the republican parliament say moves to introduce a market economy had already started.Silayev told parliament Wednesday the plan could not be implemented in full because of changing circumstances. He also said extra measures were needed in the first stage of reform to protect the population from inflation and unemployment.

"Such basic reforms as land, housing, social services, privatization and so on, can and will be realized in full. But to implement these reforms it is necessary to exercise the republic's sovereign rights," he said.

Silayev said the 500-day plan allows the 15 Soviet republics "a certain degree of economic independence." The Russian parliament on Wednesday adopted a law declaring the republic had full control of all its natural resources.

A compromise economic reform blueprint, known as "Basic Directions," was approved by the national parliament two weeks ago. It offers republics some scope to introduce their own reforms but says the center should control key resources.

Soviet President Mikhail Gorbachev has for the past month or so been using emergency powers granted by the national parliament to introduce countrywide reforms, which have only partially corresponded to the 500-day plan.

The Russian parliament has been at odds with the Kremlin for months over whether national or republican laws have supremacy.