https://www.bbc.co.uk/news/business-67505811
In Wednesday's Autumn Statement, Mr Hunt said he would cut National Insurance from 12% to 10% from January, at a cost of £10bn.
He also extended or made permanent several tax breaks for business.
But the Institute for Fiscal Studies (IFS) said the chancellor was able to do this because he had not increased spending on public services.
When factoring in rising prices, that meant that unprotected departments would face budget cuts of more than £20bn by 2027-28.
"Put another way, the tax cuts are paid for by planned real cuts in public service spending," IFS director Paul Johnson said.
"We've seen councils in financial difficulty, maybe we'll see more of that. We've seen quality of service in prisons and the court system deteriorate, maybe there will be more of that," said Ben Zaranko, a senior research economist at the IFS.
The Resolution Foundation, which campaigns for better living standards for those on low and middle incomes, came to a broadly similar conclusion and called the plans "implausible".
"The idea that there is as much scope to cut spending today as there was in 2010, given the deterioration of public services is far-fetched," it said.
'Tax-cutting rhetoric'
The think tank also said the government would set a "grim" new record for living standards going down in this parliament.
It said that despite the "tax-cutting rhetoric" of the Autumn Statement, there had already been £90bn of tax rises announced by the government - so taxes would rise by the equivalent of £4,300 per household between 2019-20 and 2028-29.
It added that people's purchasing power had been stagnating for 20 years, and that recent pay rises just reflected the reality of rising prices.
By the end of this parliament, it expects households to be £1,900 worse off than they were at the start.
On Wednesday, the Office for Budget Responsibility (OBR), the government's economic forecaster, said that the UK's tax burden was going up "to its highest level in the post-war era".
