KIEV, July 23 — More than 42,000 people have joined a class-action lawsuit against President Viktor Yanukovych over the past seven days, seeking to remove him through impeachment, an opposition party reported Monday.

The lawsuit, submitted by Arseniy Yatseniuk, the leader of the united opposition group, to the High Administrative Court, seeks to remove Yanukovych for alleged “usurpation of power” following controversial changes to the constitution in October 2010.

Any Ukrainian citizen may join the lawsuit and the opposition groups have set up committees across Ukraine to help people join the action by signing the petition.

“As of the morning of July 23, 42,380 persons have signed the petition within the ‘Ukraine vs. Yanukovych’ lawsuit,” the opposition Front for Changes group, reported in a statement.

Meanwhile, the group also reported a number of attacks, some orchestrated by local governments across Ukraine, aimed against the action, which has been gaining momentum.

“On July 18, representatives of the city government in Kharkib have attacked the ‘Ukraine vs. Yanukovych’ tents,” the group reported.

Valentyn Topchiy, the head of the law enforcement department at the Kharkiv city government, was reported to have led the attack, which had involved a number of police officers detaining the protesters.

The campaign to impeach Yanukovych for alleged violations of the constitution and persecution of opposition leaders has begun on July 16. The campaign calls for the collection of signatures under the petition against Yanukovych.

The lawsuit is based on a controversial ruling by the Constitutional Court on October 1, 2010, which had triggered an overnight change of the constitution, with Yanukovych receiving a massive power boost. The court is widely thought to be controlled by Yanukovych loyalists.

“According to the Article 5 of the Constitution, nobody can usurp the state power,” Yatseniuk wrote in the lawsuit to the High Special Court. “However, starting from October 1, 2010, the defendant made actions that he had no right to make.”

Yanukovych is under fire from the West over the politically tainted jailing of former Prime Minister Yulia Tymoshenko, the country’s top opposition leader. European Union leaders boycotted Euro 2012 football championship games in Ukraine last month over her imprisonment.

Although there is a little chance that the opposition groups will successfully impeach Yanukovych, the campaign will serve to energize opposition supporters ahead of the October 28 parliamentary elections.

Opposition groups plan to pursue the case even if the Ukrainian court rejects the lawsuit.

If the High Special Court rejects the lawsuit, the opposition group will file the suit at the European Court of Human Rights or other international courts.

“There will be more signatures,” Maximus333, a blogger, wrote on Monday. “The main thing for the lawsuit is to reach the European court. There is a plenty of evidence of the usurpation of power and disrespect for the law.” (tl/ez)