Nathan Tinkler arrives at the Independent Commission Against Corruption on Thursday.

Nathan Tinkler arrives at the Independent Commission Against Corruption on Thursday. Photo: Edwina Pickles

Nathan Tinkler's dim view of the Independent Commission Against Corruption did not improve after the financially troubled mining magnate spent two hours in a windowless conference room waiting to give evidence.

By 4pm on Thursday he and his minder decided to call it a day as the current witness was still being cross-examined about exciting material such as his Ulladulla honeymoon.

''It's been character assassination for three weeks and I am looking forward to putting an end to it,'' Mr Tinkler said crossly as he left the ICAC and made his way across Castlereagh Street flanked by a sizeable media pack.

Before disappearing into the back entrance of the Sheraton on the Park, Mr Tinkler added: ''I won't be using any of her crocodile tears tomorrow, I can tell you that.''

The embattled miner was referring to the sometimes teary evidence given recently by the former Labor MP for Newcastle, Jodi McKay.

Ms McKay gave evidence that Mr Tinkler had tried to bribe her to secure her backing for his proposed billion-dollar coal terminal at Newcastle. 

When she told him she could not accept donations from him because developers were prohibited donors, Ms McKay said: "His immediate reply was, 'I have hundreds of employees and I can get around the rules that way.' "

On hearing that Mr Tinkler's company and her Labor colleague and former ports minister Joe Tripodi were behind a smear campaign to damage her re-election chances for the March 2011 state election, Ms McKay began to cry.

Through her tears, she said: "I knew they didn't want me in the seat, but this is the first time ... you know what, it's good news, because now I know.''

The ICAC is also investigating allegations that Mr Tinkler's property development group Buildev paid $66,000 to a Liberal Party slush fund, Eightbyfive, before the past state election in exchange for favourable treatment from then shadow energy minister Chris Hartcher.

When the commission started investigating the fund, Mr Tinkler emailed a colleague on April 19, 2013: "Who is ICAC?"

The reply prompted him to respond: "Oh mate ur f--king kidding me ..."

Mr Tinkler's solicitor, Harland Koops, also complained to the inquiry that his client had been waiting for days to give evidence.

"Mr Tinkler changed his travelling arrangements to accommodate the commission," Mr Koops said. ''He's now been waiting for two days.''

"Is he in a hurry to go somewhere?" Commissioner Megan Latham asked.

"Yes, he's in a hurry to go back to where he resides in Singapore," Mr Koops replied.

"Well, he can do that after tomorrow. We'll get to him tomorrow," Ms Latham said.

Suspended Liberal MP Chris Spence will give evidence first on Friday before Mr Tinkler is called to give evidence.

Former police minister Mike Gallacher, who was previously the minister for the Hunter, resigned from cabinet this month after it was alleged at the inquiry that he "hatched a corrupt scheme" with Buildev executive Darren Williams to channel illegal donations into the fund.

The money was paid by Mr Tinkler's horse stud, Patinack Farm, in what the inquiry has heard was a sham to hide the fact that Buildev was making payments in breach of the 2009 ban on developers donating to political parties.

Newcastle Liberal MP Tim Owen announced on Monday that he would not recontest next year's election because it was "highly likely" that Buildev had contributed to his election campaign without his knowledge.

In an expletive-laden email, Mr Tinkler complained after the state election that he had also donated to the Nationals and they were doing "f--- all" to approve a proposal by Buildev for the $1 billion coal terminal in Newcastle.