He also told Fairfax Media that any policy uncertainty from the new Queensland government could be the final straw.

“Some miners have put to me that if there was to be unexpected negative moves by a new government, they may find that head office decides that they should opt for the certainty of the cost of a shutdown, rather than the uncertainty of staying in operation," Roche warned.

"At the moment it is very hard for them [the miners] to convince head office to tip in capital, or essentially to under-write their losses. So the last thing we need are policy changes that tip the balance on the preparedness of the resource company head offices to keep tipping in the capital to sustain these operations."

Roche deemed that about half of Queensland coal was being produced at a loss and said about 10% was produced at losses exceeding $US14 per tonne.

He reportedly said many of the state’s mines remained open because of “onerous take-or-pay obligations for rail and port”

“If you were to overlay a set of policy changes from left field, that might be the tipping point for some," Roche warned Fairfax in relation to those mines.

"That's a conversation that I've been urged to have as early as possible with the new set of ministers."

Some take or pay rail haulage contracts for Australian coal mines cover periods up to 12 years in length.