Undertaken by the Institute for Public Policy Research, it claims the chancellor could raise £147m a year through the special tax rate.
Downing Street distanced itself from the report but opposition parties claimed Labour had ‘let the cat out of the bag’ and was planning a raft of tax rises if they win the next election.
The IPPR plan would see the IHT threshold remain at £263,000.
Above that, the 40% tax rate would be replaced by 22% marginal for up to £288,000, increasing to 40% for amounts up to £763,000.
The 50% rate would only apply to estates over £763,000.
Richard Le Tocq, head of Locate Guernsey, discusses the chancellor’s approach to high net worth individuals, and why relocation is increasingly attractive to HNWIs
The firm says that the U-turn 'does not alter the need for a fundamental review of the way we tax work' and that the current tax system is in need of reform
Legislation on the NICs changes to be brought forward in the autumn following publication of 'the full effects of the changes to Class 2 and Class 4' in the summer
Following chancellor Philip Hammond’s Spring Budget speech, we explore the key takeaways for businesses and individuals