Viktor Yanukovich, the Ukrainian prime minister, and the Ukrainian parliament have pushed for the dismissal of three cabinet members as part of a power struggle with Viktor Yushchenko, the pro-Western Ukrainian president.
The foreign, defence and interior ministers are linked to Yushchenko and have been at odds with Yanukovich.
Parliament, which is newly empowered to appoint and sack most ministers, started the process of dismissing Yuri Lutsenko, the interior minister and a key figure in the 2004 Orange Revolution that swept Yushchenko to power.
But after a debate in which Yanukovich's allies said he was not fit for office, a motion on Thursday to sack Lutsenko secured 223 votes, three short of a majority in the 450-seat assembly.
Yanukovich, who was meeting Vladimir Putin, the Russian president, in Moscow, had earlier sent a formal request to parliament to dismiss Borys Tarasyuk, the foreign minister and chief architect of the president's drive to move Ukraine closer to the West.
In addition to launching procedures against Lutsenko, the assembly also issued a resolution seeking the removal of Anatoly Hrytsenko, the defence minister, another of the president's few allies in the cabinet.
The parliamentary session was closed after the motion on the interior minister failed. It was unclear if or when the assembly might try to remove Lutsenko again, or the other two ministers.
Yushchenko defeated Yanukovich in a presidential election in the aftermath of the revolution, but he made a comeback when his Regions party came first in a parliamentary election in March.
Yushchenko made him prime minister in August after his now divided Orange allies failed to form a government.
Their rows have been magnified by constitutional amendments handing some presidential powers to the prime minister and parliament.
The president now recommends appointments to the three key ministries, subject to parliament's approval.
Yanukovich enraged Yushchenko in September by telling Nato officials that Ukraine could not apply for fast-track Alliance membership and has long sought the foreign minister's departure.
He turned on Tarasyuk on Wednesday after the foreign ministry for a time sought a postponement of his planned visit to the US next week until he formally submitted guidelines for the talks.