Ross has protested about police behaviour

Ross, 58, has pleaded innocent to three charges related to driving under the influence of alcohol.

Her lawyer, Stephen Paul Barnard, has filed a petition over his motion to dismiss the breath tests.

A previous hearing dismissed the claim that Ross had felt intimidated and been coerced to take the test.

It was rejected by Tucson City Magistrate T Jay Cranshaw, who allowed the results to be used at trial.

Ross had allegedly fallen over when she was stopped by police in Arizona during the incident on 30 December.

She had protested in court about one of the officers, saying: "I felt a threatening tone from him. You know, like a command, a demand."

Her trial, originally set for 9 September and then 9 December, is now scheduled for January.