Queensland’s deputy premier tried to “repair” his relationship with Clive Palmer after he quit the Liberal National Party.

Queensland’s deputy premier sent Clive Palmer a letter seeking to repair their relationship a month after the mining tycoon referred to him as a thug and a bully, a court document shows.

The war between Jeff Seeney and Mr Palmer escalated in November 2012 when Mr Palmer resigned from the Liberal National Party, of which he was a life member and major donor.

Earlier that month, he described Mr Seeney as a thug who “has a long history of being a bully”.

Mr Palmer was frustrated at the government for overlooking Waratah Coal’s bid to build a rail line from the Galilee Basin in western Queensland to the Abbot Point terminal, near Bowen.

But in December 2012, Mr Seeney sent Mr Palmer a letter reiterating his willingness to “meet with you personally on a regular basis”.

“I value the progress we have made today on repairing the relationship between your company and our government,” the letter said.

The correspondence was tendered to the Supreme Court in Brisbane as part of a challenge by Waratah Coal against Mr Seeney, who in October 2013 rejected its rail bid.

The court appearance on Wednesday also comes a day after Mr Seeney said he would refer all government correspondence with Mr Palmer to the Crime and Misconduct Commission.

Last month, the deputy premier described him as a “crook” in parliament.

Waratah Coal’s legal counsel Shane Doyle told the court the government made a mistake in dismissing its rail bid.

“We submit the decision rejecting the application was made in administrative error,” he said, adding the government had failed to properly consider the potential economic benefits of the proposal and Waratah’s strong financial position.

In March last year, the government announced Indian mining giant GVK and billionaire Gina Rinehart’s Hancock Coal would work with freight rail company Aurizon to build rail infrastructure to Abbot Point.

Waratah’s proposal, to build a line along a slightly different corridor, was put to the former Labor government in late 2011 but rejected two years later.

The hearing before Justice Martin Daubney continues.