NICOLA Sturgeon has been criticised for missing the Holyrood vote which will tonight widen the income tax gap between Scotland and England for the middle class to £1500.

At exactly the same time only SNP MSPs back the controversial measure in Edinburgh, the First Minister will be more than 500 miles away speaking to politicians in Paris.

READ MORE: Nicola Sturgeon defends trip to France after 'jaunt' jibe 

She is due to address deputies of the National Assembly, the lower house of the French parliament, about Brexit and EU nationals living in the UK.

The Scottish Tories said Ms Sturgeon was “running away” from her unpopular policies.

The row comes ahead of a vote on the Scottish Rate Resolution for 2019/20, a vital part of the budget process that sets the rates and thresholds for income tax north of the border.

Under SNP plans, the threshold for the higher rate of income tax will be frozen at £43,430 while it rises to £50,000 south of the border from April, an effective tax cut.

It means around 120,000 high earning Scots face an effective marginal tax rate of 53p in 2019/20, leaving them around £130 a month worse off than their English counterparts.

Scottish Tory finance spokesman Murdo Fraser: “

It’s understandable that the First Minister is keen to keep her distance from the most unpopular SNP policies. Nicola Sturgeon has broken her promise to the Scottish people and is raising taxes - running away will not fool anyone.”

Ms Sturgeon also visited the US and Canada earlier this month.

Labour MSP James Kelly said: “Nicola Sturgeon has spent more time on business class flights than she has in working-class communities lately, and missing the income tax vote to be in France is just the latest example."

A Scottish Government spokesperson said: “At this time of maximum Brexit uncertainty it is more important than ever that the Scottish Government proactively engage with European and other international partners, and the First Minister’s visit is a vital part of that.”

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Ms Sturgeon is expected to take part in the final vote on the Budget on Thursday.

The minority SNP administration struck a deal with the Scottish Greens last month to pass the budget, giving more money to councils and agreeing to a locally-set tourist tax and workplace parking levy.

However the Greens will abstain on today’s vote as they feel Finance Secretary Derek Mackay didn't raise taxes enough to fund public services.

Green MSP Patrick Harvie said: “We have a government reluctant to anger right-wing voices by going further on income tax. That’s a misjudgement.

“We shouldn’t be letting policy on income tax be influenced by the kind of people who are currently losing their grip over car parking

."

Mr Mackay said: “Our decisions have resulted in a more progressive tax system, protecting those lower and middle income taxpayers, while raising additional revenue to invest in our public services and the Scottish economy. Our policies on tax make Scotland an attractive place to live, work and invest

.”

Ms Sturgeon's absence will not affect the arithmetic of the vote, as missing ministers are 'paired' with Ruth Davidson, who is on maternity leave.

In her speech today, the FM will say Brexit is “self-defeating” and vow her government will continue to encourage EU citizens, including 7000 French people, to remain in Scotland

She will say: “For me, this is one of the saddest parts of Brexit. The UK Government is proclaiming the end of free movement as a victory – instead, it is a self-defeating measure.

“It removes opportunity from millions of people. It is an approach which is especially damaging to Scotland. Without freedom of movement there is a danger that our population will start to decline. We could face workforce shortages in rural areas, in our universities, in our care and health services. "European nationals are not only very welcome in Scotland. They are crucial to our well-being.”