Queensland is using weasel words around competition to justify rejecting national rules to make data centres invest in new renewable energy, after promising almost $2 billion of taxpayer funds last year to support coal and gas in the state.

The Queensland LNP government on Tuesday took the extraordinary step of dissenting from an entire state and federal ministerial communique that included backing for a federal proposal to require data centres to invest in new renewable energy sources to power their operations.

Queensland and the CLP government in the Northern Territory both refused to endorse the proposal – welcomed by other states, including NSW and Victoria, where most of the investment is going – in the hope that data centres would be drawn to their existing and untapped fossil fuel reserves.

Queensland treasurer and energy minister David Janetzki on Wednesday justified the decision by saying Queensland wants data centres to be allowed to source additional electricity “on a competitive basis”, which in his terms included gas.

“It’s setting that 100 per cent mandate for new additional investment into the system, we think actually precludes more commercial outcome possibilities,” Janetzki said on Wednesday, on stage at the Australian Clean Energy Summit with New South Wales (NSW) energy minister Penny Sharpe.