Mr Dunne called on the Government to respect the Commerce Commission's final pricing recommendation to lower copper broadband prices.
"The Commerce Commission is an independent regulator that has been given the important task of setting prices fairly in a monopoly market. It is outrageous that the Government should even consider overriding this apolitical process", he said.
"The United Future Party will not support that."
NZ First Deputy Leader Tracey Martin said Kiwi families would end up paying more than they should for their internet "in another shonky deal crafted by the Government" if the commission's recommendation was overturned.
"We will vote against any legislation that seeks to overrule the Commerce Commission's final pricing recommendation or that tries to delay its implementation."
Mr Dunne said he wasn't sure that legislation to override the commission was ever a serious option for the Government, ``but I think it would have been an unacceptable course to have followed anyway and I certainly wouldn't be supporting it.
"If you have an independent process via the Commerce Commission you can't sort of operate that on the basis 'well, you make the right decision otherwise we'll override the position you adopt'.''
Mr Dunne said the Government had not so far sought his support for legislation to override the commission.
Labour Leader David Cunliffe said the announcements meant support for National's "copper tax'' had evaporated leaving it as "the only party in Parliament supporting a crony deal for Chorus''.
Labour supported the independent regulatory process undertaken by the commission and its decision to cut copper prices which would reduce broadband prices for all New Zealand families he said.
"National must not add to its crony hall of shame that includes, Rio Tinto, SkyCity, Warner Brothers and others by intervening to bail out Chorus.''
The Green Party and Mana Party Leader Hone Harawira also underlined their opposition to Government intervention on copper prices.
Mr Harawira said a quarter of Kiwis would never have access to the new UFB fibre network Chorus was helping build.
"We're not voting for any Bill that tries to make people who will never have UFB pay for it to be put into homes in Remuera.''
Green Party The National Government should respect the decision of our independent pricing regulator and not look to interfere in copper-line internet pricing to bolster Chorus's profits, said Mr Hughes.
Green Party information technology spokesman Gareth Hughes said the The National Government should respect the commission's decision "and not look to interfere in copper-line internet pricing to bolster Chorus's profits''.
"The Green Party would also not support action by John Key to kick the issue to touch by delaying the implementation of the Commission's ruling set to take place on December 1, 2013. We need lower prices now.''
Two months ago consumer and industry groups launched a campaign opposing Government intervention, saying it amounted to a $600 million tax on broadband customers.
In August Communications and IT Minister Amy Adams proposed setting Chorus' wholesale charge for copper-line services between $37.50 and $42.50 a month, the same price as faster fibre services, and up to $10 higher than the Commerce Commission's draft proposal last year.
In his final determination Telecommunications Commissioner Stephen Gale set a price of $34.44 per line, up from the $32.35 he originally proposed but still 23 per cent less than the $44.98 Chorus currently charges retailers for copper access.