SCOTLAND’S food and drink industry – worth around £4 billion a year to the economy – faces a major threat from the UK Government’s attempts to hold on to devolved powers post Brexit, a watchdog has said.

In a letter obtained by The National, Ross Finnie, chair of Food Standards Scotland, intervened in the ongoing power grab row over proposals by Theresa May for Westminster to take control of a raft of areas being repatriated from Brussels for up to seven years.

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Finnie also warned that efforts to improve public health north of the Border, including fighting obesity, would be undermined by the UK Government’s plans.

The former LibDem minister warned if food standards and labelling became reserved, even temporarily, Scottish businesses in the sector may not have their needs taken into account when new regulations are being devised by ministers in London.

“I would be failing in my duty to the Parliament if I did not write to you to set out my concerns,” said Finnie in the letter to Russell.

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“It seems likely the UK Government (UKG) will argue the need for cross-UK consistency as being essential for trade once the UK leaves the EU as regulatory assurance is intrinsic to securing trade deals.

“However, if those matters are reserved to the UKG to determine, it will be difficult for Scottish stakeholders’ voices to be heard, or for the needs of businesses or consumers in Scotland to be given priority.”

Last week, Scottish Conservative leader Ruth Davidson mocked Nicola Sturgeon’s comments that the power grab could limit the Scottish Government’s ability to fight poor diet and obesity during First Minister’s Questions. But Finnie’s letter to Russell supports the First Minister’s position.

In the letter, dated March 22, Finnie said: “The Scottish Government has recently completed a consultation on developing a strategy to reduce obesity in Scotland. Reservation to the UK of policy and legislation on food standards and labelling mean Scotland would not have competence to regulate in this area to improve public health.”

The UK Government – and Scottish Tories – said a single set of regulations on food standards and labelling is needed post Brexit to “protect the single UK market”. Finnie warns this stance puts UK business interests over those of Scottish consumers.

“As chair of a public health body, protection of the internal market and facilitation of trade at the expense of Scotland being able to determine the right market intervention measures to ensure public health protection suggests a potential shift that is too much towards protecting businesses’ interests at the expense of consumers’ interests,” he wrote.

Finnie also underlined the UK Government had a poor record on responding to public health concerns raised by Scottish ministers in areas where reserved and devolved powers overlap. He pointed to the Scottish Government’s wish to tackle junk food advertising, but said UK co-operation had not been forthcoming. He also cited Scottish ministers’ wish to fortify bread with folic acid to prevent birth defects such as Spina bifida, adding that “the UKG has steadfastly shown no signs of intervening in the market to improve health outcomes”.

Obesity is a major public health issue in Scotland with the country having some of the highest incidences in Western Europe.

UK and Scottish ministers will meet today to try to break the deadlock over the Clause 11 row.

The UK wants the Scottish Government to recommend Holyrood gives consent to the bill but the latter has refused saying it is not in Scotland’s interests.

A spokesman for Russell said: “This warning exposes the very real threat posed in areas like food standards and public health by the UK Government’s attempted power grab – and underlines why we are so determined to defend the powers of the Scottish Parliament and the founding principles of devolution.”

A Government Spokesperson said: "The EU Withdrawal Bill ensures that all powers that are currently devolved, stay devolved. That means anything they can do now within EU rules, they will still be able to do after exit day, including on food standards and safety.

"But we want more powers to pass to the devolved administrations. So the EU Withdrawal Bill will transfer more powers to Holyrood - the vast majority of powers in otherwise devolved areas will now pass directly to the devolved legislatures after exit day. The Bill provides certainty for people and businesses on how laws will work across the UK.

"The 24 policy areas being discussed are currently controlled by the EU and operate on a EU basis. The devolved legislatures operate within the flexibility provided by EU law. We are working with the Scottish and Welsh Governments to design new common approaches that will be bespoke to the UK and allow for more flexibility."