The government has backed away from two explicit commitments to establish a register to help stamp out multi-national tax avoidance – by claiming there was never a commitment in the first place.

Announced by Kelly O’Dwyer in the lead-up to the 2016 federal election, the register was to bring Australia in line with G20 commitments on transparency, by publicly listing the identities of who ultimately owned shell companies and benefitted from them, including for tax purposes.

In April 2016, O’Dwyer, then assistant treasurer, said “we agree there needs to be a registry of beneficial ownership in our country”, as the government was attempting to hose down local voter outrage over multinational tax avoidance.

Since then, progress on the register has stalled.

In response to a Guardian Australia inquiry in December on the “promise to create a public register of beneficial ownership of shell companies”, a spokesman for the assistant treasurer, Stuart Robert, said “we remain committed and we’re considering options”.

Now the Treasury department says there was never any commitment from the government to establish the register.

In response to a question on notice from the Greens senator Peter Whish-Wilson on the status of “the commitment to establish” the register and its timing, the government changed tack.

“No commitment to implement a register has been made by government,” the Department of Treasury responded.

“The government is considering what action may be needed to increase the transparency of beneficial ownership of companies.”

Instead, the department pointed to the Open Government National Action plan announced in December 2016 “to improve transparency of information of beneficial ownership and control of companies available to relevant authorities”.

“The government’s objective is to assist relevant authorities to address illegal activities such as tax evasion, money laundering, corruption and terrorist financing.

“As part of this commitment, the government released a public consultation paper seeking views on the details, scope and implementation of a beneficial ownership register for companies.”

That consultation period ended in March 2017. There has been no move to draft legislation.

Whish-Wilson said it was a “ministry of truth” moment, a reference to the Orwellian language from the novel Nineteen Eighty-Four regarding the government department which concerned itself with lies.

“The government went to the last election promising a registry of beneficial ownership,” he said.

“But today they are saying they made no commitment to a registry of beneficial ownership. This is worthy of the Ministry of Truth.

“Unfortunately, it’s an all too familiar trend. Long after the announcement to deflect public outrage, the lobbyists walk the halls and get their way.

“This shows that this government serves at the pleasure of the rich and the powerful.”

The register was first floated after the Panama Papers release, which revealed how some of the world’s wealthiest citizens and companies used a law firm to minimise the amount of tax they paid, through the creation of shell companies.

The aim of the register was to trace back who ultimately benefited from the companies, helping Australian tax authorities track down tax avoiders.

Whish-Wilson said it was crucial. “Tax avoidance is at epidemic levels.

“Yet this government is too gutless to introduce even the most basic transparency measures because of their wealthy donors. This is a pathetic back-down but the fight doesn’t stop here.”

Labor has committed to introducing a register, if elected, vowing to also include trusts in the final product, as well as reintroducing legislation which will require private companies with turnovers in excess of $100m to publish their tax legislation.

The assistant treasurer’s office was contacted for comment.