Mr Stewart told the court he did not read every contract

Mr Stewart is being sued by Harrah's Entertainment which wants the singer to return the $2m (�1.1m) he was paid to perform at the concert.

The 60-year-old star called off the December 2000 show months after undergoing surgery for thyroid cancer.

"There was nothing there. No strength," he told the jury.

New dates

Mr Stewart added: "I was petrified. I was scared. This was my livelihood."

The Rio hotel and casino in Las Vegas, which is owned by Harrah's, is suing Mr Stewart for breach of contract and is seeking the return of the advance paid to him for the show, plus interest and legal fees.

Mr Stewart's lawyer has said the show was cancelled because of the thyroid cancer surgery he underwent in May 2000, and that his offer to play a rescheduled date had been rebuffed.

Mr Stewart said his voice only recovered in time to begin a world concert tour in June 2001.

He estimated he had since performed 150 shows and said he would be willing to play up to two concerts at the Rio if Harrah's would agree.

Commitment

However, Gary Loveman, Harrah's chief executive, said earlier this week that another performance date would not be as profitable for the casino.

Harrah's lawyer Stephen Morris asked Mr Stewart about the $25.3m (�13.9m) contract the singer signed in November 2000, committing him to promoter Clear Channel Entertainment for 100 shows on the world tour.

Mr Stewart said he did not know if his representatives had told the Rio about the contract.