Devolution is “under threat as never before,” because of the “increasingly interventionist approach” to politics taken by the Conservatives, Angus Robertson has claimed. 

The comments from the External Affairs minister came as he gave evidence to MPs on the Scottish Affairs Committee as part of their investigation into how the UK Government works with the devolved administration. 

He said that prior to Brexit successive UK governments had “generally and rightly recognised that devolved matters were the responsibility of devolved institutions”.

But he said that since the vote to leave the European Union took place in 2016 ministers south of the border had adopted an “increasingly interventionist approach into devolved policy matters”.

Mr Robertson said that had led to an “erosion of the protections provided to devolved institutions”, adding there had been a “hollowing out” of the Sewel Convention – which sets out that the UK should not legislate in devolved areas without the consent of the devolved administrations.

Mr Robertson said: “This is something that the UK Government has decided to do, it has chosen to override the Scottish Parliament withholding consent and in many cases the Welsh Senedd not granting consent too.”

He said the “effect of the UK Government’s actions is to constrain the powers and responsibilities of devolved institutions”.

Mr Robertson added: “While there are good examples of collaboration, the simple reality is that the actions of the UK Government since 2016 especially have caused significant damage to the devolution settlement, which was established with overwhelming public support.”

While he stressed it had “not always been so”, the Scottish External Affairs Secretary added that the “position has deteriorated badly since 2016 as a consequence of Brexit, so much so that the very existence of devolved government is under threat as never before”.

He told MPs the problem was not just confined to Scotland, saying similar concerns had been raised in Wales.

He said that the devolution settlement had envisaged annual meetings between the UK foreign secretary and the Scottish Government’s external affairs secretary, but added: “When I met James Cleverly I was the first External Affairs Secretary to actually have a meeting in the by then 24 years of devolution, 23 years perhaps.”

Mr Robertson also said that a meeting he was “supposed to have” with current Foreign Secretary Lord David Cameron “was cancelled and no subsequent date has yet been found for that”.

Speaking about the situation generally, Mr Robertson said that “more often than not” letters from Scottish ministers asking for meetings “aren’t even replied to”.

He added that “that’s the norm, unfortunately, with things”.

Mr Robertson told the committee the “significant churn in Whitehall of ministers” could be a reason for this, saying ministers were sometimes “not in office for very long” and may not understand “why things like this really matter”.