The Gaps in Support All Party Parliamentary Group (APPG) has written to the Chancellor, Rishi Sunak, to challenge claims he made in a letter to one of his own constituents.
In a statement, the APPG said: "The Chancellor, in response to a question about the lack of economic support being offered to three million ‘excluded’ workers, told his constituent that three million is ‘not a number that I recognise’.
"He went on to claim that ‘I do not think that it is right to describe those people as excluded’."
The statement added: " The APPG on Gaps in Support has provided the Chancellor with detailed statistics and information on groups who have had no meaningful support from the Government during the pandemic. The APPG’s Targeted Income Grant Scheme proposal to the Treasury shows that there are 2.93million people, across several groups, who have had little or no support from the Government, according to ONS and SEISS statistics.
"These people have been denied support unfairly, despite being taxpayers, because of inadequate support scheme rules. The self-employed and small business sector make up 99.3 per cent of the business population. They are the life blood of the economy and should be the engine of our recovery."
The letter to Mr Sunak, which has been signed by Jamie Stone MP, the chair of the Gaps in Support APPG, said: "We appreciate that these are challenging times for the Treasury, but that is no excuse for failing to take time to understand this issue, especially when you have been presented with the evidence.
"These taxpayers have been frozen out of their legitimate support, through no fault of their own and in their time of greatest need when the Government should be supporting them."
Rebecca Seeley Harris, the former Senior Policy Adviser to the Office of Tax Simplification, who supports the work of the APPG, added: "He (Mr Sunak) needs to acknowledge the situation and that the problem is real. He seems to be putting up a brick wall. There are people who are at their wits' end and have no idea how they are going to live."
Tracy Brabin, the Labour and Co-op MP for Batley & Spen, who has raised the plight of Yorkshire workers who have been excluded from Government support, said some people were feeling "absolutely desperate".
"We are bemused as to why Rishi Sunak is taking this hardline position,'' she added.
She said the people affected were taxpayers and entrepreneurs the economy would need to recover from the pandemic.
A Treasury spokesperson said: “Our Self Employment Income Support Scheme is one of the most generous in the world and has helped nearly 3 million people claim almost £20 billion pounds.
“The scheme is targeted to provide support to those most in need - lower earners and those that rely solely on their self-employment income. Many of those who do not qualify will benefit from other measure in our unprecedented £280 billion package of support, such as furlough.
“We acknowledge that it has not been possible to support everyone in the way they might want, but we continue to work with stakeholders and keep our schemes under review and will set out the next stage of our economic response at Budget.”