THE relationship between the governments in London and Edinburgh is "under pressure like never before" over Brexit, a senior SNP MP has claimed.

Chair of the Scottish Affairs Select Committee Pete Wishart told MPs "things have to change dramatically" and urged "parity of esteem" between the governments of Scotland, Wales and the Northern Ireland Executive with Westminster.

During a Commons debate marking 20 years since devolution, Wishart said: "What we have found is that inter-governmental relations are under pressure like never before."

He added: "They have been challenged within an inch of their lives by Brexit."

The relationships between the governments have not kept pace with the developments of devolution, he claimed, adding: "The machinery for dialogue and engagement has not kept up with the evolving dynamics of devolution.

"On a sub-political level, the work between civil servants, for example, continues unabated."

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In a recent report, the Scottish Affairs Select Committee recommended increasing the powers of the Joint Ministerial Council where the leaders of the devolved governments can engage with Westminster.

Wishart also warned any calls for a second Scottish independence referendum from the Scottish Parliament must be adhered to.

He said: "This is a matter for the Scottish people. The Scottish people should always get what the Scottish people want."

Tory MP David TC Davies, who opposed the creation of a Welsh Assembly before the referendum in 1997, said he would not go back on the referendum result.

He added: "As a result of losing, I felt as a democrat it was very important that we respected the will of the people of Wales.

"So there was no suggestion afterwards that we should try to challenge the decision in the courts or say that people had been tricked by Labour."

He continued: "We simply respected the fact that the people of Wales had spoken.

"I want to put on record right now as a Conservative and someone who opposed the Welsh Assembly 20 years ago, that in my view it would be absolutely wrong to try and undermine the Welsh Assembly, take away its power, or get rid of it in any way at all."

Conservative David Duguid said the "spirit of devolution" of decisions being taken closer to home "has not taken root entirely" within the Scottish government.

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The Banff and Buchan MP said: "Successive Labour and SNP Scottish governments have hoarded power in Holyrood and governed primarily, it's been suggested, for the central belt.

"While English city regions are getting more control over their own affairs to accompany growth deals, Nicola Sturgeon is ensuring Scotland remains rigidly centralised."

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LibDem MP Jamie Stone was heckled by SNP MPs after he suggested an SNP government were overseeing “almost a dictatorship".

SNP MP David Linden responded by calling for a second independence referendum.

The Glasgow East MP said: "If they are still confident that people in Scotland wish to be a part of the United Kingdom, ask them.

"If you are confident that they will do it, then put the question to the people and we will have a vote."

Labour's shadow Scotland minister Paul Sweeney said some of the powers the Scottish Parliament has to change income tax or welfare policy are not being used.

He added: "The existing powers of the Scottish Parliament must be used effectively – that being said, new powers may well be needed to make a real difference in tackling the problems (Scotland faces)."

Cabinet Office minister Kevin Foster, asked about a survey of Conservative Party members which suggested 63% believed leaving the EU was more important than keeping the Union together, said: "I'm clear that I'm a unionist and I want to see this Union remain together.

"That poll is absolute rubbish."