Chancellor Rachel Reeves faces pressure to impose tax increases on middle-income households instead of targeting wealthy individuals to close an estimated £30billion fiscal gap.
A prominent think tank has argued that broadening the tax burden across average earners would represent the "least economically damaging" approach to addressing the Treasury's financial shortfall.
The recommendation challenges Labour's election commitment to leave income tax, VAT and National Insurance untouched.
The Institute for Government suggested that attempting to generate significant revenue exclusively from the wealthiest citizens would prove "difficult and risky", advocating instead for measures affecting those on typical salaries.
This marks the second such proposal within two days calling for the Chancellor to reconsider her tax strategy.
The Institute for Government, which receives funding from Lord Sainsbury's Gatsby Foundation, stated that tax increases should "fall on those with average incomes".
Tom Pope, the organisation's deputy chief economist, said: "This autumn, the Chancellor finds herself in a difficult position. With tax rises all but inevitable, she should reject the path of least resistance, often taken by her predecessors, of raising taxes in an inconsistent way based on what seems easiest."
The think tank cautioned that wealthy individuals possess greater mobility than typical workers, meaning even modest numbers relocating abroad could create tax revenue deficits.
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The Chancellor finds herself in a difficult position
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The Treasury has reaffirmed its position on protecting workers' pay packets.
A Treasury spokesman said: "We are protecting payslips for working people by keeping our promise to not raise the basic, higher or additional rates of income tax, employee National Insurance or VAT."
Despite these assurances, economic experts suggest maintaining such commitments may prove increasingly difficult.
Paul Johnson, former director of the Institute for Fiscal Studies, has proposed raising the basic income tax rate.
The former director of the Institute for Fiscal Studies has proposed the Chancellor should raise the basic income tax rate
| GETTYThe Resolution Foundation has also suggested Ms Reeves should hike income tax by two per cent - while slashing the National Insurance rate by the same amount.
The move could raise £6billion for the Government as income tax is also paid by pensioners and self-employed Britons, while workers on a salary would see the hike cancelled out by the NI drop.
The think tank pushing for the plans harbours strong ties with senior figures within the Government.
Chancellor Rachel Reeves is confronting mounting fiscal pressures | POOL Rain Newton-Smith, who leads the Confederation of British Industry, stated: "When the facts change, so should the solutions."
Lord Sainsbury, who previously chaired the Sainsbury's supermarket chain, has contributed more than £20million to Labour over the past thirty years.
Economists estimate Ms Reeves must secure between £20billion and £50billion when she presents her budget on November 26.