Cash for everyday public spending in Northern Ireland has only increased by £4.2 million and there is no additional capital funding, Finance Minister Conor Murphy has said.
Almost all the extra £411.9 million announced by Chancellor Rishi Sunak on Wednesday will go on a one-off response to Covid-19.
Extension of the jobs furlough and support for the newly self-employed will help the recovery, Mr Murphy said.
He added: “Almost all of this money is one-off funding for the Covid response, which is welcome as we look to the recovery phase. However, it still leaves us with a flat-cash budget for mainstream public services.
“It is also disappointing that there is no extra capital money to spur economic recovery.
“An investment-led approach is absolutely critical given we have never fully emerged from years of austerity measures.”
Mr Sunak has extended many pandemic-related business and household support schemes.
He used his Budget to extend the furlough scheme and Universal Credit increase as part of a £65 billion lifeline for the UK economy as it emerges from the pandemic.
But taxes on business profits are set to be hiked from 2023, while income tax thresholds will be frozen, meaning more people will be dragged into paying.
The furlough scheme means the Government pays the wages of people who cannot work amid coronavirus pandemic restrictions.
It pays employees placed on leave up to 80% of their salary, up to a maximum of £2,500 a month.
Mr Murphy said: “The biggest concern of many employers is wage costs, so the extension of the furlough scheme until the end of September is good news for workers, families and businesses.
“However, I am concerned that asking employers who may not be fully operational to find the cash for these wage costs could lead to redundancies.
“It’s also welcome that the Chancellor will support newly self-employed people.”
He said the direction of travel for dealing with replacement EU funding is a “significant” cause for concern.
He said: “The British Government continues to bypass the Executive, taking control of funds from Westminster instead of enabling funding decisions to be taken by locally-elected ministers.
“I raised this with the Chief Secretary to the Treasury today.”
Angela McGowan, CBI Northern Ireland director, said this Budget succeeded strongly in protecting the economy now and kickstarting recovery.
The Government’s plans to raise business profit corporation tax from 19% to 25% could result in significant challenges for Northern Ireland.
Stormont has been attempting to reduce the local tax rate to compete with the Republic of Ireland’s 12.5% tariff and attract more inward investment.
Ms McGowan said: “Moving corporation tax to 25% in one leap will cause a sharp intake of breath for many businesses and sends a worrying signal to those planning to invest across the UK.
“This is a particularly acute concern for Northern Ireland’s post-Brexit competitiveness on the island of Ireland.
“The Government and the Executive must now have a laser-like focus on Northern Ireland’s competitive position in the round, including fundamental reform of business rates, investment in skills and a relook at how Northern Ireland competes with the Republic’s corporation tax rate of 12.5%.”