David Christopher Laipato, 27, went on trial in the ACT Supreme Court on Monday on charges of choking the woman insensible and threatening to kill her in February last year.

Laipato has pleaded not guilty.

The court heard the pair – who are still in a relationship – had celebrated a friend's birthday at a Civic apartment.

The Crown, led by Sam McLaughlin, alleges the pair argued about 2am before Laipato pinned her to the bed and choked her insensible.

The accused allegedly said words to the effect of: "I'm going to kill you" during the incident.

He left soon after.

The prosecution alleges the woman then vomited and called the police.

Laipato was arrested outside the building a short time later.

But defence lawyer Paul Edmonds said the alleged victim had invented the allegations because she believed Laipato had been unfaithful.

Mr Edmonds said his client admitted to arguing with the woman, but denied choking or threatening her.

He said paramedics who attended the scene reported no marks on her neck.

The defence told jurors the woman had made a statement to police at the time, but had since written to the authorities in an attempt to retract the allegations, which she now says are false.

Mr Edmonds argued the original statement had been made when the alleged victim had been emotional and suffering mental health problems.

The woman, from the witness box, told the court the pair had argued in the lift because Laipato had admitted to using drugs and hanging around with bad influences.

The fight continued in the unit, with the woman pushing his face a number of times, she said.

She told jurors that he only pushed her back once, did not choke her, and left after she continued to shove him.

The trial before Chief Justice Helen Murrell continues on Tuesday.