The US Supreme Court’s chief justice, William Rehnquist, failed to turn up Monday for the first day of court hearings since undergoing cancer treatment but could still take part in key decisions.

Rehnquist, 80, a conservative whose illness could become a factor in any dispute over the US presidential election, announced last month that he was suffering from thyroid cancer. But he also said he would be back at work on November 1.

Court spokeswoman Cathy Arberg said that Justice John Paul Stevens had taken charge of Monday’s hearings.

Stevens “made a statement indicating that the chief justice could not be there but that he reserved the right to participate in the cases that were being argued, on the basis of briefs and tapes of arguments,” said the spokeswoman.

The Supreme Court also issued a statement by Rehnquist in which he said doctors had advised him to stay at home.

“I underwent a tracheotomy nine days ago and, at the suggestion of my doctors, am continuing to recuperate at home. According to doctors, my plan to return to the office today was too optimistic.

“I am continuing to take radiation and chemotherapy treatments on an outpatient basis,” he said.

Rehnquist went on: “While at home, I am working on court matters, including opinions for cases already argued. I am, and will continue to be, in close contact with my colleagues, my law clerks and members of the Supreme Court staff.”

Rehnquist led the Supreme Court panel that decided to halt a recount in the 2000 election, handing Bush a 537-vote lead in the state of Florida and, with that, the US presidency.

With Tuesday’s vote expected to be very close, the Republican and Democratic parties have prepared armies of lawyers to fight any dispute over voter irregularities.