A massive hike in probate fees detailed in the Budget has prompted a fresh wave of criticism of the Government by Tory MPs.
A £215 cap on the costs of executing wills is being raised to £20,000 under an overhaul that will raise £300 million for Treasury coffers.
But the reforms were branded a "death tax" by worried Conservative backbenchers.
Conservative MP Oliver Colvile told the Daily Mail: "I have real concerns about this. We absolutely do not need a death tax – which is what this sounds like."
Jacob Rees-Mogg said: "I also have concerns about the probate tax. I see that it is likely to be judged by the national statistics people as a tax rather than as a charge, and I do not think it right that the Government should introduce stealth taxes.
"Probate charges should relate to the cost of the probate work, which is broadly irrelevant to the size of the estate. There might be some more work for bigger estates, but the difference will not necessarily be as large as has been proposed."
A sliding scale of fees is being introduced starting at £300 for estates worth between £50,000-£300,000 and ending at £20,000 for those above £2 million.
When the proposals went out to consultation, 810 of the 831 responses were opposed to reforms.
Budget documents said the Government expects the new fee structure to raise around £300 million a year.
It comes after Downing Street insisted Theresa May remained "fully committed" to reforming National Insurance contributions (NICs) for the self-employed despite a Tory backlash.
In a Brussels press conference on Thursday, the Prime Minister promised to listen to concerns raised by Conservative MPs and said there would be no vote until the autumn on the £2 billion hike in contributions for the self-employed announced in the Budget.
Labour claimed the promise amounted to a "partial U-turn" on proposals tabled by Chancellor Philip Hammond on Wednesday.
But Mrs May insisted that Mr Hammond's planned 2% hike in Class 4 NICs for the self-employed was "fair", when considered in the light of the abolition of the separate Class 2 payments as well as improvements to the benefits received by self-employed people.
A review of modern employment practices by RSA chief executive Matthew Taylor, due to report over the summer, will be followed by a Government paper which is expected to include proposals to extend benefits such as parental leave to the self-employed.