Suggestions of a rift between George Osborne and Work and Pensions Secretary Iain Duncan Smith have been rejected by a senior minister.
Universities minister David Willetts said he was "not aware" of any friction between the two men.
The intervention came amid reports that the Chancellor and Mr Duncan Smith had a blazing row over the up-front costs of proposals for reforming the benefits system.
According to the Mail on Sunday, Mr Duncan Smith complained that the Treasury was being "rude and arrogant" towards the DWP.
He is said to have singled out mandarin Clare Lombardelli for particular criticism, after she dismissed his plans as "unaffordable and unworkable".
But Mr Willetts told Sky News' Sunday Live programme: "I'm not aware of any such issue.
"All I can say is that all of us are working hard on saving money in our departments. And very important in that is saving money in the biggest department of the lot on spending, the Department for Work and Pensions."
He added: "I know sitting around the Cabinet table with them that George Osborne and Iain Duncan Smith are both absolutely committed to reforming our welfare system which just is not working at the moment - and, of course, to achieving significant public savings in that area."
Mr Duncan Smith wants to introduce a new benefits system that would ensure people in work are always better off than the unemployed.
He has insisted the changes will save tens of billions of pounds over the long-term. However, the Treasury is believed to be concerned about the initial £3 billion outlay at a time when Budgets are being slashed across the rest of Whitehall.