Living standards think tank the Resolution Foundation said the decision to bring forward to 2019 planned increases in income tax thresholds to £12,500 for basic rate and £50,000 for the higher rate would "overwhelmingly benefit richer households".
The IFS also warned that many public services will continue to feel squeezed for some time to come.
As UC is rolled out, around one-third of benefit claimants will end up £1,000 or more worse-off and one-third at least £1,000 a year better-off than they would have been under the previous system.
"Now we know", he said.
Treasury chief Philip Hammond announced boosts to public spending and an income tax cut for millions of British workers on Monday, in the first significant loosening of purse strings in eight years.
Mr Hammond still also has to fund the promised £20 billion-a-year increase in NHS funding in England over the next five years announced by Mrs May in June.
The Budget has been branded "a bit of a gamble" by a respected economic research group.
As well as the tax cuts and increased departmental spending, the Chancellor set out one-off bonuses for defence, schools and local authorities after being given positive forecasts for the public finances by the OBR.
"Yes, the OBR reduced borrowing forecasts so he was able to find more money without committing to more borrowing.
The tax cut is a major boost for families" take-home pay and will take effect just days after Britain formally leaves the European Union next year.
Bone, one of the hardest of hard Brexiteers, attracted criticism previous year after he and fellow Tory hardliner Chris Chope slept in the Houses of Parliament for three nights to propose 73 pieces of legislation, stopping other backbenchers' proposals being debated. "What will he do then?"
"He's going to struggle to reimpose austerity having announced its end". That number is significantly higher than the UK's plan to tax internet businesses with revenue of over £500 million. "More likely he would just allow borrowing to persist at a higher level".
Meanwhile, public spending is set to remain on a relatively tight leash even after the government's so called "giveaway", with total expenditure estimated at £812.8 billion in 2018, before rising to £955.3 billion in 2023.
The Chancellor sought to reassure voters and shore up the morale of the fractious Tory MPs Theresa May needs to back her Brexit deal by peppering his speech with spending pledges and a surprise income tax cut, The Guardian reports.
Pointing out the likes of Google, Facebook and Amazon, the tax will be imposed on those firms with a global revenue of £500 a year and the increase in tax will put £400 million back in the United Kingdom government, when it comes into place in April 2020.
Hayley said: 'Although I am at the top of my pay bracket for my job, the change to thresholds will help Philip because he is looking for promotions, so he could stay below the higher tax bracket.