UPDATED 5.40pm: MP Chester Borrows has been charged over injuring two women with a car during a Trans Pacific Partnership (TPP) protest.

LISTEN ABOVE: Expert in traffic law, barrister Tony Beach talks to Larry Williams

The Whanganui National MP and Deputy Speaker of the House of Representatives told NZME he would defend the charge of careless driving causing injury for the March incident in Whanganui.

MORE: Police investigate whether MP ran over protester's foot

He would not comment further.

A charge sheet at the Whanganui District Court today showed a 59-year-old man named Kerry James Borrows – his birth name - was charged with operating a vehicle on Liverpool St carelessly, “and thereby caused injury to Tracey Treadwell and Denise Lockett.”

Detective Senior Sergeant Neil Forlong would not confirm names, but said a 59-year-old man has been charged in relation to an incident on Liverpool St on March 22.

Crown prosecutors will have a lot to prove to show Mr Borrows is guilty of careless driving.

Auckland barrister Tony Beach told Larry Williams there are a number of elements to the careless driving charge which prosecutors will have to prove.

"Was he driving. Was he driving carelessly. Possibly he may not have even been on a road."

The role of Parliament's Deputy Speaker is now under question after it emerged he's been charged by police, and it's not the first time a Deputy Speaker has been in hot water.

In 2000 then Deputy Speaker Ian Revell stepped down from the post, over a $40 parking ticket and allegations he'd threatened police over it.

Whether Mr Borrows will also step down remains unknown.

He's offering no comment on the matter and the Speaker's Office is yet to clarify its position.

It is not yet known when Borrows will appear in court.