Bronwyn Bishop has cancelled her next taxpayer-funded overseas trip amid ongoing controversy over her travel expenses, raising fresh questions about her ability to stay on as federal Speaker.

The embattled Mrs Bishop had been planning to travel to the United States for an international summit of parliamentary speakers in New York at the end of August.

It is understood planning for the trip was well advanced, but Mrs Bishop quietly withdrew her travel plans in the wake of public fury over her travel expenses at home and abroad.

"The Speaker was considering travelling to New York for that meeting but she has since decided not to," Mrs Bishop's chief of staff and spokesman Damien Jones confirmed.