Net migration to the UK hit a record 745,000 in 2022, new figures show.
The Office for National Statistics (ONS) said the updated data replaces the previous estimate of 606,000, after making revisions to reflect "unexpected patterns" in migrant behaviour.
However, ONS data for the 12 months up until June 2023 showed a lower net migration figure of 672,000.
This has led to suggestions the figure may be on a downward trend, but The ONS said it was "too early to tell".
Separate Home Office visa and asylum data showed there was little change in the total number of people seeking asylum in the UK, at 76,000 for the year to the end of September 2023. There were 56,042 people in hotel accommodation.
The news comes around a week after the Government's controversial Rwanda Bill, aimed at reducing the number of illegal migrants, was declared illegal by the Supreme Court.
Despite widespread support from the Tory right, it has faced criticism since its conception for violating human rights and its significant cost.
The prime minister will soon publish a new updated agreement with Rwanda in a bid to address the court's concerns around "refoulement" – the potential for refugees rejected by the central African country to be sent back to the country they are fleeing.
Sunak will also try to come up with emergency legislation that he says will enable parliament to "unequivocally" declare Rwanda a safe destination for asylum seekers.
But a leading lawyer told parliament earlier this week that the planned new treaty with Rwanda would be a "historically worthless piece of paper".
Today, Labour responded to the migration data, accusing the government of "utter failure" over its stewardship of immigration and the economy.
"Within that figure, there's a huge increase in work visas, which shows the Government hasn't done what it needs to do on skills," said the opposition leader Sir Keir Starmer
"Within that number, there is a rising number of asylum seekers and disclosure that the hotel bills are going up and up."
The figures also prompted widespread backlash from prominent Conservatives – Sir Jacob Rees-Mogg said he was "embarrassed" that the Tories had not managed to deliver on their migration pledges, and ex-Home Secretary Suella Braverman described them as a "slap in the face to the British people".
She called on the government – which she was a member of until last week – to "act now", with policies including introducing an annual cap on net migration and the number of health and social care visas given out, as well as raising the salary threshold for people to come to the country, closing the graduate visa route, and limiting the number of dependents.
The latest data is likely to pile pressure on Rishi Sunak, who pledged at the start of his premiership, in December last year, to "stop the boats".
As well as his promise to put an end to illegal migration, he has also assured to cut the number of people coming into Britain legally, responding to voter worries about the pressure on public services and housing shortages.
Net migration is calculated by looking at the number of people arriving in the UK when both immigration (people coming to the UK) and emigration (people leaving the UK) are taken into account.
From July 2019, a few months before the last general election, to June 2023, the total estimated UK net migration stood at 1,611,000.
That total reflects net arrivals of 1,829,000 people from outside the EU and net departures of 81,000 EU citizens and 137,000 British citizens.
Interior Minister James Cleverly said the government wanted to eliminate abuse of the visa system to get numbers down.
"The government remains completely committed to reducing levels of legal migration," he added.
Elsewhere, the government released its Autumn Statement on Wednesday, in which Chancellor Jeremy Hunt announced a £10 billion National Insurance cut for millions and an uplift in benefits.
The Conservatives claimed they had delivered the biggest tax cuts in decades in a move to boost the UK's stagnant economy and top up incomes.
But the UK's overall tax burden is still on course to hit a record high.
The percentage of the nation's income being paid in tax is set to rise to its highest level in 80 years, according to the Office for Budget Responsibility.
