KIEV, April 1 – Three opposition leaders on Monday called on thousands of their supporters to join a rally in front of Parliament Tuesday to support a resolution that schedules Kiev's mayoral election on June 2.

The date, however, is likely to be opposed by the ruling Regions Party, which says it is still waiting for clarification from the Constitutional Court on the matter.

The disagreement raises the stakes in what may become a major political battle this year that many believe would have serious impact on the outcome of presidential election in March 2015.

Opposition groups traditionally have strong popular support among Kiev residents, but the city has been de-facto run over the past three years by an appointee of President Viktor Yanukovych.

A victory by an opposition candidate at the Kiev vote in June would boost morale for opposition parties ahead of the presidential election. It would also provide control over key infrastructure in the capital at a critical time in case the presidential election triggers major anti-government street protests.

“If you are not indifferent to the process that is taking place in the capital, if we, the Kievites, are confident that we can change the situation, let’s come and join the protest action near Parliament,” Vitaliy Klichko, the leader of the opposition Udar party, said in a video address.

Arseniy Yatseniuk, the leader of opposition Batkivshchyna party, and Oleh Tiahnybok, the leader of the nationalist Svoboda party, in the same video address,also asked for support.

“We need you on the streets for our joint victory,” Tiahnybok said.

The rally near Parliament is scheduled at 10:00 AM, while lawmakers are supposed to start debating the Kiev election resolution at noon.

At the rally, the opposition groups are expected to announce the name of a single opposition candidate that will run for the Kiev mayor post.

Oleksandr Yefremov, the leader of the Regions Party in Parliament, said recently the party will not support the resolution unless the Constitutional Court issues its own ruling on the matter.

Some 48 Regions Party lawmakers appealed to the court earlier this year asking for the clarification on the date of the election. The court started to consider the appeal on Friday and the ruling may take at least one month.

The opposition groups do not trust the court and believe the ruling may postpone the vote in Kiev until after the presidential election in March 2015, a ruling that would most likely trigger political clash and confrontation. (tl/ez)