A majority of SNP voters do not support the party’s “progressive” income tax policy and want to pay the same or less than the rest of the UK, according to a new poll.

Three-quarters oppose party leader and First Minister Humza Yousaf’s plan to tackle poverty by making higher earners pay more tax.

He is proposing another income tax band for middle and higher earners, favouring a campaign by the Scottish Trades Union Congress (STUC) for a 44p rate on earnings between £75,000 and £125,140.

The Fraser of Allander Institute has found this would raise little more than a quarter of the £200 million projected by the STUC.

The last SNP tax rise means anyone earning more than £27,850 will pay more tax than if they lived south of the border.

Scottish income taxpayers earning between £43,662 and £125,140 pay 42p in the pound on that portion of their earnings. For those on more than £125,140 the rate is 47p.

Between £43,662 and £50,270 Scottish income tax payers also have a marginal tax rate of 54% because national insurance thresholds, which are controlled by Westminster, align with the income tax rates set by the UK government.

Mr Yousaf’s commitment to raising income tax is likely to stir tensions at the SNP conference in Aberdeen where the party is already facing accusations that is losing touch with the electorate. The party is also struggling to plug a £1 billion gap in the government’s budget which could herald spending cuts.

Polling by Panelbase, for The Sunday Times, found that only 10% of respondents believed workers on £27,850 or more should pay more tax than the rest of the UK, while 65% said the levy should be the same as other British workers and 16% said Scots should pay less.

For those who voted SNP in the 2021 Holyrood elections 54% thought tax should be uniform across the UK with 19% saying Scots should pay less. Almost nine in ten (87%) of Labour voters want to pay the same or less.

Liz Smith, the Scottish Conservative finance spokeswoman, said the poll findings were “a devastating verdict from Humza Yousaf’s own supporters on any plans he is considering to hit Scots with more tax rises.

“Scotland is already the highest taxed part of the UK on his watch, yet increasing rates further seems to be his only answer to plugging the £1 billion black hole the SNP has created in our public finances.

“Even his own voters recognise that a greater tax burden hinders any prospect of the economic growth we desperately need and that it leaves Scotland with less money to invest in public services.

“Hopefully this backlash from SNP voters will mean that Humza Yousaf finally abandons his misguided proposals to widen the tax gap even further.”

Comment: Time for SNP to build bridges with Westminster