The demonstrators are protesting to the commission's decision on August 11 not to register the bloc for next month's parliamentary elections. Tymoshenko has called the commission's decision illegal.
The top 10 candidates on the bloc's list are all former legislators.
Candidates from Prime Minister Viktor Yanukovych's party and from President Viktor Yushchenko's Our Ukraine group were successful in registering with the commission.
Eight of the commission's 15 members represent the pro-Russian governing coalition led by Yanukovych, whose bid for the presidency was thwarted by the Orange Revolution that broke out after tainted elections in late 2004.
Tymoshenko was a leader of that bloodless revolution, along with Yushchenko.
She also served as prime minister in 2005 ahead of a high-profile dispute with Yushchenko.
(compiled from agency reports)
Spotlight On Yuliya Tymoshenko
READFormer Prime Minister YULIYA TYMOSHENKO has long been a controversial figure in Ukrainian politics. A former economist and head of Unified Energy Systems (EES) of Ukraine from Dnipropetrovsk in eastern Ukraine, Tymoshenko served as deputy prime minister for energy in the cabinet of Viktor Yushchenko, when he was prime minister under former President Leonid Kuchma. She has faced legal troubles linked to corruption allegations both in Ukraine and in Russia, although all cases against her have now been dropped. Tymoshenko was a firebrand of the opposition movement during the 2004 Orange Revolution, leading demonstrators to surround the presidential administration and issuing ultimatums to the Kuchma government.
In March 2005, President Viktor Yushchenko named her prime minister, a post that she held until September of that year. In August, on the occasion of the six-month anniversary of her appointment, Tymoshenko spoke with RFE/RL at length, discussing, among other things, the then-looming gas conflict with Russia and the likelihood of a "difficult and dirty" battle in the upcoming parliamentary elections....(more)