In his opening speech, he said some political forces are seeking to usurp power in Ukraine.
Yushchenko has accused pro-Moscow groups in parliament of encouraging lawmakers from blocs that support him to switch sides. He says this activity goes against the constitution and must be halted.
Several thousand people today gathered in central Kyiv to protest Yushchenko's threat to dissolve th Verkhovna Rada, which is controlled by a pro-Russian coalition.
On March 31, Kyiv saw rival rallies between supporters of the president and backers of pro-Russian Prime Minister Viktor Yanukovych.
(with material from agency reports)
RFE/RL Belarus, Ukraine, And Moldova Report
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