A Treasury minister has attacked cabinet colleagues who have demanded extra money for their departments in an outspoken speech.
Liz Truss said it was "not macho" to push for bigger budgets, singling out the boost for the NHS as a "one-off".
Defence Secretary Gavin Williamson and Home Secretary Sajid Javid have reportedly been pushing for extra cash.
Ms Truss also took a swipe at Michael Gove over the environment secretary's planned crackdown on wood burners.
"Too often we're hearing about not drinking too much, eating too many doughnuts, drinking from disposable cups through plastic straws, or enjoying the warm glow of our wood-burning Goves... I mean stoves," she said in a speech at the London School of Economics.
"I can see their point: there's enough hot air and smoke at the environment department already."
Former minister Ed Vaizey told BBC Radio 4's Today programme Ms Truss had achieved her goal of getting noticed with her "full frontal assault" on Mr Gove.
Mr Vaizey also criticised Foreign Secretary Boris Johnson for undermining Prime Minister Theresa May, warning that "having climbed up the ladder" on Brexit, the government kept getting pushed "back down the snake".
He said Mr Johnson's decision to pursue an "entirely separate" Brexit policy to the prime minister and to fly to Afghanistan to miss a vote on Heathrow expansion had encouraged other ministers to think "if it's alright for Boris it's alright for me".
Quizzed about Ms Truss's comments in a Q&A with members of the Scottish Parliament, Mr Gove said: "You should judge us as a government by our actions."
Over the past year the cabinet had "worked together and we've sought to work collaboratively", he added.
Analysis by BBC Political Correspondent Laura Kuenssberg
Brexit has been driving rival Tory factions crazy for many, many months. It's extremely difficult to corral them in a minority government. Different ministers sounding off about the misperceptions of their opposing gangs don't even always lead hacks to raise a pencil.
But that instability has fuelled an atmosphere where party discipline seems on the point of breaking down, even though with the whips in overdrive, government is achieving its most important objective of getting its business through Parliament.
Yet the Cabinet seems sometimes to be creating the appearance of chaos where there need not be any.
The latest bout of infighting at the top of government started at the weekend, when Defence Secretary Gavin Williamson reportedly said that he could "break" the prime minister if his demands for extra cash for his department were not met.
Home Secretary Sajid Javid has also been demanding more money for police budgets, after Health Secretary Jeremy Hunt unveiled a £20bn boost in funding for the NHS.
Ms Truss, who his second in command to Chancellor Philip Hammond, hit back in article for The Daily Telegraph, telling her cabinet colleagues "it's not macho to demand more money".
"It's much tougher - and fairer to people - to demand better value for money."
The Chief Secretary to the Treasury went on to accuse them of "not been clear with the public about the tax implications of their proposed higher spending".
Speaking at the London School of Economics, she said the £20bn a year budget boost for the NHS in England up to 2023 announced by the prime minister last week would not be replicated elsewhere.
"My point to my colleagues is that any additional spending will necessarily - most likely - lead to additional taxation and we should be honest when we have that discussion," she said.
"We need to keep tax as low as possible."
Ms Truss's comments echo those of former minister George Freeman, who said that the Conservatives risked losing the next election if they made a series of unfunded spending commitments.
"We cannot have this process done by cabinet ministers going to the press and briefing against the prime minister, and putting their bids in early," he said.
The government has yet to spell out where the extra money for the NHS will come from although Mrs May has indicated that the public will have to make a contribution and the overall "tax burden" will rise.
Mr Hammond will set out the total public spending framework for the years beyond 2020 in this autumn's budget, before deciding department-by-department allocations next year.
Many Tory MPs want defence spending as a share of GDP to increase from its current level of just over 2% to at least 3% in the face of growing threats, including from Russia.