DAVID Mundell’s suggestion more powers could be transferred to the Scottish Parliament as a result of Brexit has been described as a “smokescreen” by one of the First Minister’s Europe advisors.

SNP MEP Alyn Smith hit out as the Scottish Secretary said leaving the EU will fundamentally change the devolved settlement in Scotland and he wanted to encourage “debate and discussion” on the issue.

In an interview yesterday, Mundell signalled the change could be equivalent in scale to those brought about by the Calman and Smith commissions in Scotland.

“One of the most significant differences that we could feel in Scotland post-Brexit is in the changes to the devolution settlement,” he said.

But Smith, who sits on the First Minister’s Standing Council on Europe, told The National he thought the claim highly unlikely.

“We must remember that anything in terms of Holyrood competencies would be negotiated by [the UK Government] the very same people who have proven at every opportunity they want to limit Holyrood competencies,” he said.

“I think David Mundell is saying these things as he has nothing else to say, and he is using this idea as a smokescreen.”

The claims are similar to ones put forward in recent weeks by the former SNP cabinet minister Alex Neil who voted Leave.

Smith did not mention Neil by name, but added: “I don’t think any nationalist giving credence to this obvious smokescreen is helpful.”

Mundell steered the 2016 Scotland Act, which granted Holyrood new powers over tax and welfare, through the UK Parliament.

In a Sunday Times Scotland interview, he indicated further powers could be transferred to Holyrood as a result of the Brexit vote, and stressed that no functions would be “re-reserved to Westminster”.

He told the newspaper: “The devolution settlement could be affected to a similar extent as that proposed by Calman and Smith...We need to work out how the UK will work best after powers are repatriated to the United Kingdom, and which powers will be repatriated to Scotland. Whatever the circumstances, no powers will be re-reserved to Westminster.”

Mundell later told BBC Scotland “a number of powers and responsibilities” would have to return to the UK or devolved administrations.

Speaking on the Sunday Politics Scotland programme, he said: “What I think hasn’t been fully understood and is only just beginning to be debated – which is what I want to encourage – is that by leaving the EU that will have a fundamental change on the devolved settlement here in Scotland and indeed elsewhere in the United Kingdom.”

Asked for examples of powers which would return, he told the broadcaster: “For example, and I think self-evidently, agriculture and fisheries are two of the issues currently exercised at European level.

“Both the NFU in Scotland and the Scottish Fishermen’s Federation are coming forward with their views as to how these sort of powers should be taken forward post leaving the EU. But there will be significant powers in the area of the environment and there are also powers in relation to the criminal justice system as well.”

During the BBC interview Mundell refused to say whether he would back single market membership for Scotland – despite both his and Ruth Davidson’s previous assurances they would back Scotland remaining in the single market.

The Scottish Tory leader insisted in July the UK should maintain single market membership, but this month her party ditched this support, voting against protecting Scotland’s place in the single market in a Holyrood debate. Mundell was also asked whether he backed Davidson’s position that the UK Government should not block an independence referendum. After being asked six times, he eventually stated “my position isn’t inconsistent with what Ruth said.”

The fishing industry is among the few sectors that welcomed Brexit because of its potential to lift EU restrictions on where and how much can be fished.

Under Brexit fishing restrictions would be repatriated to Westminster, who could devolve them.

Bertie Armstrong, chief executive of the Scottish Fishermen’s Federation said: “Brexit has monumental significance for the nation’s fishing industry and our coastal communities in terms of providing the opportunity for a significant increase in economic activity. It is vital that fishermen across the UK speak with a united voice to ensure that the UK and devolved governments fight for the interests of these communities in the forthcoming negotiations.”

A Scottish Government spokesman said: “We will set out proposals in the next few weeks that will keep Scotland in the single market even if the rest of the UK leaves, and will include substantial additional powers for the Scottish Parliament.”