Liz Truss tonight appeared to rule out appointing an ethics advisor to police her behaviour if she becomes PM.
The Foreign Secretary, who is favourite to replace shamed Boris Johnson, said that ethics couldn't be "outsourced".
Mr Johnson's last ethics advisor, Lord Geidt, quit in June after clashing with the PM - with Ms Truss appearing to indicate he would not be replaced.
Lord Geidt's predecessor Sir Alex Allan also quit when he ruled Priti Patel broke the Ministerial Code in a bullying probe - but Boris Johnson overruled him.
Meanwhile Ms Truss also refused to reassure anxious Brits that they will receive support from the government as energy bills soar in the coming month.
Speaking at a hustings event in Birmingham, Ms Truss said: "I do think one of the problems we've got in this country is we've got numerous advisors and bodies and rules and regulations, but for me it's about knowing the difference between right and wrong."
She added: "I don't think you can outsource ethics to an advisor, we need ethics running through the government."
Rival Rishi Sunak disagreed, saying he would replace Lord Geidt, telling the party faithful that the public - and particularly floating voters - expected high standards to be upheld.
He said: “I would reappoint the independent advisor on ethics and I would make sure they had the power and responsibility to hold leaders to account.”
It comes as candidates face pressure to get a grip on the unfolding energy bills crisis.
Ms Truss declined to say she'd "fully protect" people from rising bill.
Mr Sunak re-iterated to the Tory faithful that the Foreign Secretary's "unfunded" tax cuts would make little difference to those on benefits and none at all to pensioners - describing them as a "moral failure".
In a dig at Ms Truss, who has spoken gushingly of her admiration for Margaret Thatcher, Mr Sunak said: "All these people who understand Margaret Thatcher's economics (referring to her former Chancellor Nigel Lawson and Tory grandee Norman Lamont) are supportive of my economic plan."
He added: “Millions of people are going to face the risk of destitution this winter, literally millions. And if we don’t do anything to avert that I think it would be a moral failure of the Conservative government.”
The blue-on-blue griping over the economy shows no sign of abating as the leadership contest goes into its final days.
Ms Truss again slammed cash payments to families as "Gordon Brown economics", and complained people must “avoid talking ourselves into a recession”.
While not ruling out extra help, she said her "first priority" is cutting taxes - and her second is boosting energy supply.
She admitted "in any fiscal event a Chancellor has to look at people on fixed incomes" - but did not spell out how she might help.
The leadership favourite continued to reiterate her controversial tax cuts will fuel growth, again declining to outline her strategy in detail.
Asked if she could promise hard-up Brits, including pensioners and those on benefits that she would provide vital support, she told host John Pienaar: "We're not going to sit here and write the budget."
She again stated: "I don't believe in taking money in taxes before giving it back as benefits."
Ms Truss said: "I'm a Conservative, I believe in low taxes, I believe in companies succeeding, I believe in companies making profits so that they're able to hire more workers, that's what I believe and that's the platform I'm standing on."
In one revealing slip, Ms Truss said that with her tax cuts "we can still afford to pay off the debt", before correcting herself saying "start paying off the debt - after three years".
Making her pitch to the party faithful, she said she would "unleash the opportunities of Brexit " and said she would legislate for single-sex spaces.
Ms Truss voiced her support for grammar schools, stating: "The answer is yes, I will allow new grammar schools, absolutely.
"I will also allow new free schools as well.
"I am a big fan of free schools like the Michaela School which is fantastic, and we need to allow the good schools to expand and set up more branches right around the country."
There were protesters outside the venue, with chants of "Tory scum, get out of Brum" and "refugees are welcome here" audible as Tory party members arrived.
Tonight is the tenth of 12 events held around the country for Tory party members - who account for around 0.2% of the population - to probe the candidates before deciding who should be the next PM.
The winner will be announced on September 5, assuming power the following day.
People arriving at the NEC were greeted by two rival merchandise stalls - offering items including branded mugs, in support of "Ready for Rishi" or "Liz for Leader".
Earlier today Mr Sunak lashed out at his rival's economic plans, warning Ms Truss could pour "fuel on the fire " with her controversial tax cuts.
Speaking ahead of this evening's hustings, the former chancellor warned that the leadership favourite could cause spiralling inflation if she takes office.
It is the latest blue-on-blue attack as the cost-of-living crisis deepens, with questions over Ms Truss's response to the misery facing millions of Brits.
Mr Sunak, speaking to broadcasters, said he understood tax cuts "may sound attractive at first, but if they risk stoking inflation and actually do nothing to help poorer people and pensioners, then they actually are going to be bad for everyone".
"I think people know if something sounds too good to be true, it probably is," he said.
Ms Truss suggested she believes some proposals to deal with the cost-of-living crisis are a "short-term sticking plaster".
Asked by broadcasters what her solutions to the crisis were, Ms Truss said: "First of all I will make sure people have more money in their pockets to deal with the very serious issues we face, whether it is food prices, or fuel prices.
"Secondly, I will make sure that we deal with energy supply, because what we need is more resilient supply here in Britain: that is about getting more gas out of the North Sea, it is about moving forward faster with things like nuclear energy to make sure we deal with those supply issues.
"What I am not about is a short-term sticking plaster, I am about dealing with the serious issues of energy supply and making sure as the United Kingdom we are resilient in energy."
