According to the OBR forecasts, unemployment is set to soar to 7.5% in the second quarter of 2021 - with 2.6 million people out of work - falling to 4.4% by the end of 2024.
By 2025 the economy will still be 3% smaller than anticipated in March.
Sinn Fein MLA Conor Murphy has hit out at the announcement by Chancellor Rishi Sunak, which he said would not support the health service or the most vulnerable in society. "And our economic emergency has only just begun".
The economy, which tanked into a historic recession owing to pandemic fallout, was forecast to rebound by 5.5 percent next year and by 6.6 percent in 2022.
He warned that with borrowing at this level, underlying public debt is rising towards 100% of annual GDP.
Jeremy Stretch, head of G10 FX strategy at CIBC Capital Markets, will be watching how the Bank of England reacts to Sunak's spending plans to see whether it maintains a significant degree of quantitative easing over the medium-term after a larger than expected increase in the support measure earlier this month.
But Sunak is not expected to give pay rises to public sector workers such as nurses and teachers who have played key roles during the Covid-19 outbreak.
Turning to global development, Sunak said spending 0.7 percent of Gross National Income (GNI) on overseas aid - the United Nations target - was "difficult to justify at a time of unprecedented crisis".
Announcing the foreign aid cut at his one-year spending review on Wednesday, Mr Sunak said the government would instead spend 0.5% of gross national income on overseas aid.
David Cameron, whose coalition government anchored the 0.7 percent target in law, said abandoning it would be a "moral, strategic and political mistake".
The Government faced condemnation from charities and a potential Tory revolt when legislation for the move comes before Parliament.
"I join others in urging MPs to reject it for the good of the poorest, and the UK's own reputation and interest".
Liz Sugg, a junior minister at the Foreign Office, has quit, arguing that the decision "will diminish our power to influence other nations to do what is right".
The Chancellor set out a almost £3 billion Restart programme to help get people back into work.
Mr Sunak made various spending pledges to fight coronavirus, including £900m for Northern Ireland as part of packages for the devolved administrations.
"Next year, to fund our programmes on testing, personal protective equipment, and vaccines, are allocating an initial 18 billion pounds".
Sunak confirmed that the National Health Service would receive a boost totalling £3.0 billion ($3.9 billion, 3.3 billion euros).
There will be £27 billion spent on economic infrastructure in 2021-22. No new trade agreement has yet been reached with the European Union.
He did however freeze any increase in business rates when they kick back in again in April.
Confederation of British Industry chief economist Rain Newton-Smith said the Spending Review "lays the foundations for a brighter economic future" but "ambition must be matched by action on the ground".
"One minute we hear loud praise from the Government for the work that we do, the next, it's a draconian pay freeze".
Several senior members of the ruling Conservative Party, including former foreign minister Jeremy Hunt, also criticised the decision, hinting at a possible rebellion in parliament.