By Shihar Aneez and Ranga Sirilal
COLOMBO (Reuters) - Sri Lanka's main opposition said on Wednesday the chief justice, facing an impeachment motion moved by the ruling party, must be given a chance to cross-examine witnesses amid a standoff between the judiciary and the government .
The dispute has raised the risk of a destabilizing clash, with both sides on a collision course since President Mahinda Rajapaksa's ruling party filed the motion against Shirani Bandaranayake, Sri Lanka's first female head of the Supreme Court, last month.
The United States, the United Nations and the Commonwealth have raised concern over the impeachment move and have called on the government to ensure the independence of the judiciary.
John Amaratunga, a legislator in the main opposition United National Party and a member of the impeachment committee probing the charges, said the chief justice must be given a chance question witnesses.
"The chief justice or her lawyers must be provided an opportunity to cross-examine witnesses and documents collected," he told reporters. "It is only then that the select committee has to determine whether the chief justice is required to disprove the charges."
Parliament Speaker Chamal Rajapaksa, the elder brother of the president, has appointed an 11-member select committee, of whom seven are from the ruling party, to investigate the 14 charges ranging from hidden wealth to professional misconduct.
Bandaranayake recently came under criticism from government supporters for ruling against a bid by the central government to take control of an 80 billion rupee ($614.20 million) development budget, saying it had to be approved by nine provincial councils.
The opposition's request came as judges on Monday demanded an impartial and transparent inquiry into the charges, labeling the government's decision to appoint its own committee to probe the ruling party's allegations a "a blatant violation of natural justice.
Chamal Rajapaksa last week rejected a Supreme Court summons challenging the legality of the impeachment move and the composition of the select committee. The Supreme Court rescheduled the hearing to December 13 and 14.
(Editing by Nick Macfie)