MPs say the chancellor has «effectively drawn a line» under helping more than a million people excluded from government virus support packages.
Last week, the Treasury Committee published an interim report into gaps in support to firms and workers hit by the virus.
However, Rishi Sunak mounted a strong defence of his aid packages.
The committee’s chairman, Mel Stride, said on Thursday it appeared Mr Sunak was turning his back on people in need.
Last week’s report stressed that more than a million people had not received support from the government and called on the Treasury to «do whatever it takes» to protect people and businesses.
However, the chancellor defended the current system of business loans and job retention schemes after reading the committee’s initial findings.
In a letter, Mr Sunak admitted to MPs on the committee that it «is correct that some people have not been eligible» for furlough or self-employment scheme funding, while others, such as PAYE freelancers, do not have a specific scheme.
But he said that these «were the right policies for the first phase of the crisis».
Mr Sunak also stressed that the Treasury was unable to allow returns for the 2019-20 tax year to be used by people to secure self-employment support as that would create an opportunity for an «organised criminal gang to file fake or misleading returns to claim the grant».
In response, Mel Stride said: «The chancellor has effectively drawn a line under helping the million-plus people who have been excluded from support for four months.
«Despite stating that he will not pick winners and losers when it comes to sectors and businesses that need support, the chancellor has done this when it comes to households and individuals.
«The chancellor said that the schemes were designed to be open and accessible to as many people as possible, but the committee remains to be convinced that more people could not have been helped.»
Mr Stride pointed out that the chancellor initially told people at risk of losing their livelihoods that they would not be forgotten.
He said: «While the government is clear that it is moving on to the next phase of its recovery plan, it cannot just turn its back on those who are suffering.»
Mr Stride said the committee «urges the government to re-think its position».
However, Treasury spokesperson said on Thursday that the scale of its support packages had been «unmatched» by any schemes in recent history and they had helped millions of companies and individuals.
«We have kept nine-and-a-half million people in work, supported the incomes of 2.6 million self-employed people and helped businesses across the UK get through the outbreak – acting quickly to deliver one of the most generous and comprehensive packages of support in the world worth an initial £160bn.
«As part of the next phase of our economic plan to rebuild and recover the UK, we recent announced Our Plan for Jobs. We have made up to £30bn available to support, protect and create jobs, helping ensure people and businesses can come back from this crisis stronger,» the Treasury said.