A senior adviser to John Barilaro says he was asked by the former NSW deputy premier to fast-track changing a controversial US trade role into a ministerial appointment.

Mr Barilaro was later selected for the $500,000-a-year New York position, which is now the subject of a NSW parliamentary inquiry.

The former Nationals leader stood down from the posting last month following a backlash over the appointment.

Joseph Brayford, a senior policy adviser in Mr Barilaro’s office from 2019 to 2021, gave evidence in private to the upper house inquiry on Tuesday.

Mr Brayford said he received a text from Mr Barilaro last August about the plum trade role, according to a transcript published on Thursday.

He said his boss asked him to contact Investment NSW head Amy Brown “ASAP” to “request a cabinet submission converting the commissioner roles to ministerial appointments”.

The request was the first time in two-and-a-half years working for Mr Barilaro that he had received a text message from his boss asking him to prepare an urgent cabinet submission, he said.

“Nothing really surprised me with John,” Mr Brayford told the committee.

He added Mr Barilaro then told him he also wanted the London and Tokyo trade roles to be changed to ministerial appointments.

The proposition to change the way trade commissioners were appointed was put to cabinet in late September, shortly before Mr Barilaro’s October announcement he would be quitting politics at the end of the year.

Mr Brayford described his former boss as an “interesting character” and said he had never “worked with someone so keen and so ambitious”.

Mr Barilaro said he would not comment on the claims until he was asked to appear at the inquiry. He is not scheduled to testify.

The former Monaro MP has previously criticised the inquiry for failing to call him, saying the drip feed of information to the public goes against procedural fairness.

Premier Dominic Perrottet, who arrived in Japan on Thursday to open the trade commission office in Tokyo, said he didn’t want to “give a running commentary” on the inquiry.

“There’s always public scrutiny and when concerns are raised they need to be addressed in a proper way,” he said.

“It’s my job as Premier to allow that independent process to be fulfilled.”

The inquiry was earlier told the New York role was verbally offered to senior Investment NSW official Jenny West. However, the offer was rescinded after a cabinet decision to make the trade postings ministerial appointments.

Mr Brayford told the inquiry he was not aware that Ms West had been selected for the role last August, prior to Mr Barilaro’s appointment.

The inquiry previously heard evidence from Mr Barilaro’s former chief-of-staff Mark Connell that his former boss eyed the lucrative trade job more than three years ago and planned to take up the role when he left politics.

Mr Connell said Mr Barilaro told him in April 2019 the government planned to bring back several overseas trade postings, and he was “off to New York”.

Mr Barilaro disputed his former chief-of-staff’s account, describing the conversation as “fictitious, false”.

Labor finance spokesman David Mookhey said he looked forward to Mr Barilaro fronting the inquiry, describing it as “his right” to do so.

“We would urge John Barilaro to put in a written submission to the inquiry. We have requested that he do so,” Mr Mookhey said on Thursday.

A separate Department of Premier and Cabinet review, initiated by Mr Perrottet last month, is also looking at the propriety of Mr Barilaro’s appointment.

– AAP