A legal expert has said Holyrood would gain a raft of new powers in the event of Brexit.

Drew Scott, professor of European studies at the University of Edinburgh, said that powers over areas including farming and fishing, currently within the competence of Brussels, would go to Scotland.

He added this would result in a “significant constitutional debate” on the question of how these powers should be used and paid for.

Professor Scott, who advised the Scottish government before 2014’s referendum, told the BBC’s Scotland 2016 programme half of the EU’s budget is currently spent on agriculture, “so you are talking about a significant amount of money”.

“Agriculture has been reformed really since devolution and what we have seen is the Scottish Parliament has had more competence over the implementation of agricultural policy in Scotland, albeit it is still governed at EU level”, he said.

“If it were to be the case that Britain left the EU, competence for farming would come back to the Scottish Parliament, full stop.

“It would have to be financed, so a new financial deal would have to be agreed between Edinburgh and London to pay for farming, which of course is not at all included in the current Smith negotiations or anything preceding that.”

He added, however, that he was not suggesting people tactically vote to leave the EU so that Holyrood secures more powers.

The academic also said current arrangements meant the UK government influences Scottish environmental policy via the EU: “That influence over environmental policy would disappear if we were to leave the EU, which would mean that Britain would find itself with Scotland perhaps diverging perhaps even further from UK policy.

“Now there is nothing wrong with that - that was what devolution in a sense was designed to do - but it would create inter-governmental discussions that would have to, I think, deal with some problematic issues”.

He suggested a number of possible legal solutions. For example, Holyrood could adopt EU law and not change anything.

However, he added: “That would still leave the thorny question of who pays for it, because if Scottish policy towards farming or fishing or regional economic development were to diverge from the UK, then the UK may say ‘why are we paying for your more indulgent policy? We will pay you the rate we pay for the rest of the UK policy’.

“So we end up, perhaps, in a struggle about finances yet again.”