Senior Cabinet ministers have refused to say if under-fire Philip Hammond spelt out that controversial Budget reforms breached manifesto pledges on tax.
The Chancellor has faced accusations that he failed to set out the implications of the plans in meetings of the Government's top team.
David Davis said Mr Hammond did not hide the details of his National Insurance reforms from the Cabinet but declined to say if there had been warnings about breaking election promises.
Asked if the Chancellor told the Cabinet the Government was about to go against a manifesto pledge, the Brexit Secretary said he "made plain what he was going to do".
He told The Andrew Marr Show: "There was no hiding of anything. Everybody knew what we were talking about."
Pressed on whether it broke an election pledge, he replied: "yes" before adding: "no, no, you are trying to trip me up".
Prime Minister Theresa May promised to listen to concerns raised by Conservative MPs over the £2 billion hike in National Insurance contributions (NICs) for the self-employed and said there would be no vote until the autumn.
Labour claimed the promise amounted to a "partial U-turn" on the proposals set out by Mr Hammond.
But the Prime Minister insisted the planned 2% hike in Class 4 NICs was "fair" as benefits for self-employed workers have improved.
Around 20 Tories have raised concerns about the changes, including Wales Minister Guto Bebb who said the Government should apologise for breaking an election manifesto commitment not to increase National Insurance.
Boris Johnson refused to say if there was a discussion among senior ministers about NICs.
The Foreign Secretary told ITV's Peston on Sunday: "Well, we don't go into conversations that we have in Cabinet, certainly not conversations before a Budget.
"But let's be in no doubt, you have to address the disparity in the treatment between the self-employed and the employed. And it was made very clear at the time the Bill to enact the lock on the NIC was put through the House of Commons, that this applied to people in employment and you have got to address that.
"I think it is very, very clear that this Budget has got a lot of good stuff in it, particularly for those on low pay, it's raising thresholds, it's lifting the tax thresholds.
"And when it comes to the actual issue of National Insurance contributions, you have got to sort out the disparity, but you have also got to look at the overall context in which you are doing this, you have got to look at the full package that self-employed people are getting, and we will come back to that later in the year."
International Trade Secretary Liam Fox said he was "happy" with the NICs reforms.
He told Sky News' Ridge on Sunday: "I was actually happy that there was a package there that when you look at the package as a whole was a very fair one.
"I didn't think we had breached our manifesto commitments."