All overseas senior trade roles are set to be investigated by the inquiry looking into the appointment of NSW former deputy premier John Barilaro to the US job.
Labor will seek to get the inquiry's terms of references expanded and comes ahead of Mr Barilaro's appearance on Monday.
And as reports emerge in Nine newspapers claiming Premier Dominic Perrottet had offered to create a new parliamentary trade role for Transport Minister David Elliott.
The report also claims the Premier spoke to Mr Elliott about the agent-general position in London as compensation following manoeuvres that could have seen him removed from cabinet. But that didn't happen.
Leader of the Opposition in the upper house Penny Sharpe said the allegations against the Premier were very serious.
"We already know that there has been significant meddling in these positions for a long time," she said.
"The Premier can't hide behind an inquiry. This goes directly to his involvement and he needs to answer those questions straight away.
"I can indicate today that we will be seeking to expand the terms of reference of that inquiry to include all appointments for the senior Trade and Investment Commission role, obviously, including the UK agent-general."
Mr Perrottet did not hold any press conferences today but the ABC put specific questions to his office asking if he "offered to create a parliamentary trade role" or "discussed the agent general position" with David Elliott.
A spokesperson responded in a statement: "Whoever the Premier considers appointing to his ministry is a matter for the Premier alone."
The same questions were put to David Elliott but were not directly addressed.
"I'm committed to delivering the NSW government's infrastructure pipeline, which is helping transform our state, and ensuring our public transport delivers first-class services for the people of NSW," he said in a statement.
"I have no interest in working overseas again."
The Premier has declined to appear before the inquiry, according to the opposition but they say it's time for him "to come clean".
"We would expect that he'd want to provide information to the public," Ms Sharpe said.
"It flies in the face of everything the Premier has said for the last seven weeks, that these are arm's length positions ... that have absolutely nothing to do with him.
"And in fact, I think the Premier has said that it would be illegal for him to even interfere in these."
The debacle, which has been gaining momentum for weeks, has so far prompted Mr Barilaro to withdraw from the lucrative $500,000 a year New York-based job.
Trade minister and Member for Penrith Stuart Ayres has also resigned from his portfolios and leadership position in the party over concerns about his role in the selection process.
While Mr Ayres maintains he did nothing wrong, a separate inquiry will take place into whether he breached the ministerial code of conduct.
Mr Barilaro will front the inquiry for the first time on Monday and is expected to face a heavy grilling.
"The committee has many questions for him obviously," Ms Sharpe said.
"But clearly you want to understand his role in the creation of these positions, his role in the changing nature of the way in which these positions were appointed.
"And any of the discussions that he had with either Minister Ayres or Mr Perrottet, or indeed anyone else in the government as he applied for and was eventually offered that job."
Chief executive of Investment NSW Amy Brown will join Mr Barilaro in giving evidence — it will be her third appearance before the committee.
During her evidence on Wednesday, August 3 she conceded the appointment was not done "at arm's length" from the government.
A report on a separate review initiated by the Premier and conducted by senior public servant Graeme Head is expected to be made public soon.
To date, the upper house inquiry has conducted five hearings.
