Last week Chancellor Jeremy Hunt revealed National Insurance would be reduced from 12% to 10% – worth £10billion.
This will save workers, on average, £450 a year.
The PM told the Daily Express: “Hard work should pay. That’s why the Chancellor just announced the biggest tax cuts at a fiscal event since the 1980s.
“We will of course go further when we can.”
Mr Hunt said a temporary tax break allowing firms to cut their bills if they invest in new equipment would also be made permanent.
Despite the earnings bonus, millions of workers will face a squeeze on their finances with the tax burden still set to hit a record high.
Chief Secretary to the Treasury Laura Trott said: “We have set a direction of travel to grow the economy, to support businesses and to reward work.
“And we want to bring that tax burden down over time in a responsible way.
“If you are on average income, because of the changes we’ve made, your tax burden will have gone down quite significantly.
“We have turned a corner, we are going to bring taxes down but we’re going to do it in a non-inflationary way.”
The Prime Minister and Business Secretary Kemi Badenoch will host more than 200 chief executives at the Global Investment Summit at Hampton Court Palace today.
Mr Sunak hailed the £29billion cash injection in innovative sectors as making Britain a top destination for business, adding it is central to his growth plan.
It is expected to create thousands of new jobs in sectors such as tech, life sciences, renewables, housing and infrastructure.
The PM said: “Global CEOs are right to back Britain – we are making this the best place in the world to invest and do business.”
