Pakistan Tehreek-e-Insaf (PTI) chairman Imran Khan filed a petition in the Islamabad High Court (IHC) on Wednesday challenging the non-bailable arrest warrant issued by the Election Commission of Pakistan against him in a contempt of court case.Khan's counsel Babar Awan in the petition argued that the ECP had no authority to issue non-bailable arrest warrant against the PTI chief. "The warrant issued by the commission on October 12 was therefore unconstitutional," stated the petition.Awan said the arrest warrant against his client should "be set aside and proceedings initiated (by the ECP) against the petitioner" may be declared "void and unlawful". The contempt application against Khan was filed on January 23 by PTI's dissident member Akbar S. Babar who had turned against him in 2011 over alleged internal corruption and illegal funding of the party, Dawn online reported.The ECP's verdict was announced a day after a three-member larger bench of the IHC directed the commission to proceed on the contempt application according to the law. Khan and Awan are embroiled in a legal battle at the ECP and the IHC for the last three years, the report said.The October 12 order was issued by a five-member bench of the ECP after the PTI leader ignored the polls supervisory body's August 24 show-cause notice relating to a foreign funding case. Khan earlier ignored half a dozen ECP summons to appear in person.According to him, it was not within the commission's jurisdiction to conduct contempt proceedings against a member of Parliament.