THE SNP have have refused to restate their manifesto pledge to freeze the basic rate of income tax, prompting claims they intend to break it in today’s Budget.

In a heated Holyrood debate, Nationalist MSPs refused to back a Tory motion that simply restated the SNP’s own promise to voters in 2016.

Instead, the Government side deleted the vow and substituted a complaint about Westminster austerity reducing the Scottish budget.

At one point, Derek Mackay refused to give a yes or no answer when Tory MSP Murdo Fraser asked him if he still backed the platform he was elected on.

The Finance Secretary said Mr Fraser was “like an impatient child” and would have to wait another day to find out the detail of the tax plans.

At last year’s Holyrood election, the SNP promised to “freeze the basic rate of Income tax throughout the current parliamentary session to protect those on low and middle incomes” for the duration of the parliament.

Mr Mackay’s draft budget for 2018/19 is expected to widen the tax gap between Scotland and the rest of the UK by increasing the tax bill for the better off and high earners.

It is understood a fourth income tax band may be created between the current 20p basic and 40p higher rates, and an extra penny added to the current top rate of 45p.

However the extra revenue will not be enough to offset a cut to the Westminster block grant or additional pressures caused by inflation and increased demand.

Councils are predicted to suffer some of the worst cuts, with a standstill cash budget failing to cover estimated additional cost pressures of around £500m next year.

The ring-fencing of some council funds for SNP priorities such as expanded free childcare is also expected to worsen the severity of cuts in other areas, such as schools and libraries.

Mr Fraser said the government should concentrate on economic growth, not “increasing the the tax burden on hard-working families”

Mr Mackay said the UK government was “the biggest threat to the economy in Scotland”.

He said: “We want to protect and promote our public services. We also want to protect lower income earners.. use the tax system in a progressive fashion, and we also want to protect the economy.”

After the vote, Mr Fraser said: “What we have seen here is the SNP voting in parliament against its very own manifesto pledge. They have disowned that pledge, and signalled their intention to punish hard workers. They’ve misled voters, and owe them a huge apology not just for hiking their taxes, but deceiving them too.”

Mr Mackay last night said the budget’s priorities would be “stopping UK cuts, protecting public services and unlocking Scotland’s economic potential”.

He said: “This will be a budget that is good for taxpayers, good for public services and good for business. It is a budget that will deliver for Scotland.”

Scottish Labour leader Richard Leonard said ministers must use their full tax powers to eradicate poverty and inequality.

Tinkering with tax bands would not be enough to protect public services, he said.

He said: “The Scottish Parliament has the power to radically change Scotland for the better.

“We need a budget that stops Tory austerity in it tracks, not one that pretends to be progressive but instead delivers regressive cuts to services and communities.”

Patrick Harvie, co-convener of the Scottish Greens, who helped the SNP pass last year’s budget, repeated his party’s demand for fairer taxes and more money for public services.

He said: “On boosting public sector pay… I am hopeful that we have made the case for a real-terms rise for hard-pressed nurses, teachers and others who deliver vital services.”

The Scottish Retail Consortium called for any business rate rises to be capped at the CPI measure of inflation, as in England and Wales, not the higher RPI measure.

Director David Lonsdale said: “What is crucial is that Scottish Ministers follow the example set by their counterparts in Wales and England, otherwise firms here in Scotland will be paying a headline business rate higher than competitors and counterparts down south from April as well as a higher large firms rates supplement.”