Devolution is under threat from “creeping centralisation” as the UK Government take a more aggressive line on where power lies, Nicola Sturgeon has warned.

The First Minister said the shift in attitude should be a “massive concern” for all MSPs at Holyrood and ring “lots of alarm bells about the future of devolution”.

She said the Tory government was going against the intention of the landmark legislation which founded the Scottish Parliament.

The 1998 Scotland Act famously specified all the powers reserved to Westminster, leaving everything else to Holyrood by default.

However, Brexit and the repatriation of powers from Brussels had changed that, Ms Sturgeon said.

Instead of abiding by the reserved-devolved split in the 1998 Act, the UK Government was re-interpreting it to take power to itself if there was any chance to do so.

Making her twice-yearly appearance before Holyrood’s committee conveners, Ms Sturgeon accused the UK Government of “woefully inadequate” dialogue on post-Brexit trade arrangements.

She said Whitehall had not shared information or allowed Scottish input, adding: “It’s one of many areas where the experience has been very frustrating.”

Ms Sturgeon said there were aspects of Brexit, such as state aid, where the Scottish and UK governments disagreed about whether the power was devolved or reserved.

She said: “This speaks to a wider and deeper concern I have about the future. For the first time in 20 years of this institution, there is a risk that we see devolution going into reverse.

“That’s not necessarily a wholesale removal of powers, but an interpretation of the Scotland Act and the reserved-devolved split.

“Instead of a… presumption that, if there is a doubt, then you have a kind of subsidiarity principle at play [power exercised at the most local level] what we are already starting to detect is a view is to interpret things as tightly as possible in order to say they’re reserved where there is any doubt.

“That will lead to a creeping centralisation.

“I think that’s a big concern. It’s a big concern for government. But I think it should be a massive concern for the Scottish Parliament.

“When you couple that to what we’ve already seen, which is a willingness to override the consent of this parliament, then lots of alarm bells about the future of devolution.

“Even before we get into debates about greater powers or independence, the future of the current devolved settlement should be something that is concerning members of this parliament.”

She also claimed the Sewel convention, which says that Westminster, although sovereign, “will not normally” legislate in devolved areas without Holyrood’s consent had been tested and found wanting by Brexit.

She said the UK Government had “ridden roughshod” over the Scottish Parliament by pushing the EU Withdrawal Act through Westminster last year despite MSPs withholding their consent and passing their own alternative Brexit continuity Bill.

Scottish Tory constitution spokesman Adam Tomkins MSP said: “Only this week, the SNP announced it was not going to accept new provisions on VAT, assigned to Holyrood by this UK Conservative Government.

“For the First Minister to complain about the UK Government’s approach to devolution after her government has handed back a series of tax and welfare powers to the UK Government is quite something.

“The SNP does not support devolution, it supports independence.

“This is the First Minister once again trying to raise a grievance about the former, in order to try and stir support for the latter.”