Nine Ukrainian parties have formed a new bloc to shore up support for President Viktor Yushchenko as an election campaign gets under way.
The political rivalry was played out on the streets of Kiev
Mr Yushchenko, a liberal reformer, has been engaged in a long-running feud with Prime Minister Viktor Yanukovych, whose supporters are more pro-Russian.
An early parliamentary election was called for 30 September, in a bid to end the political deadlock.
Mr Yushchenko's new bloc is called Our Ukraine - People's Self-Defence.
The BBC's Helen Fawkes in Kiev says the election is expected to result in another coalition and many people are likely to feel apathetic about it.
It was only a year ago that Ukrainians last went to the polls.
Mr Yushchenko dissolved parliament in April and ordered a fresh ballot, claiming his power was being usurped.
That sparked mass protests with thousands of the president's supporters and his opponents taking to the streets.
It was eventually agreed that the vote would be held on 30 September.
Mr Yushchenko became president in January 2005 following the pro-democracy Orange Revolution, which overturned a rigged victory for Mr Yanukovych.
But Mr Yushchenko accepted his rival as prime minister after the president's allies failed to win a majority in the March 2006 election, and the two men have repeatedly clashed.