Stephen Timms has warned that a cut to universal credit and rise in national insurance will be a heavy blow to many families.
The MP for East Ham commented after the government announced plans to raise national insurance to pay for reforms to health and social care.
Mr Timms said: "Additional funding for the NHS is desperately needed, but I am very worried that the government’s means of paying for it – coupled with the cut in universal credit – will be a heavy tax blow to many hard-working families.
"We still don’t know the detail of the government’s plan for social care – or whether, in reality, they actually have one – so we’ll have to wait for the detail to make a judgment on that."
Prime minister Boris Johnson set out plans aimed at tackling Covid-19 backlogs, reform of adult social care and putting the health system on a sustainable footing on Tuesday, September 7.
Under the proposals, a total of £36billion will be invested in the health and care system over the next three years.
From April 2022, the government will introduce a new, UK-wide increase of national insurance by 1.25 percentage points - from 12pc to 13.25pc - ringfenced for health and social care.
Mr Johnson, speaking in the House of Commons, said: "You can't fix the Covid backlogs without giving the NHS the money it needs.
"You can't fix the NHS without fixing social care. You can't fix social care without removing the fear of losing everything to pay for it.
"And you can't fix health and social care without long-term reform. The plan I am setting out will fix all of these problems."
The government has pledged that no one in England will now have to pay more than £86,000 in care costs over the course of their lifetime.
However, the shadow chancellor, Labour Party MP Rachel Reeves, slammed the national insurance rate rise as a tax on jobs.
She accused the Conservative Party of breaking a promise made in its election manifesto not to raise taxes on VAT, income or national insurance.
The government is also planning to end a £20 uplift in universal credit payments which was introduced to help claimants through the pandemic.
West Ham MP Lyn Brown did not respond to a request for comment.
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