Attorney-General Chris Finlayson says he is simply "doing his duty" by raising concerns about possible breaches of human rights by his own Government's law and order regime.
Mr Finlayson has found that the plans to give police unfettered power to take DNA from those they arrest and the "three strike and you're out" law both have apparent inconsistencies with the Bill of Rights.
Under section 7 of the Bill of Rights, the Attorney-General must report to Parliament if a bill appears inconsistent.
Mr Finlayson said his concerns were therefore formally those of the Attorney-General, rather than his personally as a National MP and minister "sticking it to the National Party".
So as an MP he will still vote on party lines for both bills.
But when performing the function of Attorney-General - sometimes called "the Government's lawyer" - he said it was important he acted independently.
"The Attorney-General must not be swayed by party political considerations but must objectively come to certain conclusions."
He said this independence was missing during the "failure of the system" when the Electoral Finance Act was introduced by the previous Labour Government and the Attorney-General - Michael Cullen - did not report its apparent inconsistencies with the Bill of Rights section on freedom of expression.
Mr Finlayson believed this failure was "political".
"I just thought the freedom of expression issues were so obvious that a first-year law student would be able to identify them. And history has proved that completely right."
He said this failure made him question whether the job of vetting legislation could be carried out by the Attorney-General or should instead be given to an external legal figure.
He had now changed his mind.
The Attorney-General bases his opinion on whether a proposed law would breach the Bill of Rights on advice from the Ministry of Justice or, when it it is justice-related legislation, the Crown Law Office.
In the case of the Electoral Finance Act, the Crown Law Office concluded that it was consistent with the Bill of Rights.
Mr Finlayson, a leading lawyer before becoming an MP, said he was prepared to dissent from the advice he received.
"I don't take the view that I'm some kind of automaton and just sign off on what is given to me. I will examine the matter carefully."
Mr Finlayson's report on the DNA plan found that letting police take DNA off everyone arrested without the safeguard of judicial or other independent approval could be inconsistent with the right against unreasonable search and seizure.
His report on the three-strikes bill - an Act policy which National has introduced but is reserving judgment on supporting further - found that giving a life sentence to someone who committed a crime where the punishment was five years' jail could be inconsistent with the section protecting New Zealanders against cruel, degrading or "disproportionately severe" punishment.By Patrick Gower Email Patrick