SCRAP the Scotland Office and repair the broken relationship between Edinburgh and London, a senior group of MPs have today told the UK Government.

However, the prospect of an independence referendum makes David Mundell’s job “more important than ever”, the UK Government has said.

Twenty years on from devolution, Westminster’s cross-party Scottish Affairs Committee (SAC) says the UK Government should consider replacing the Scotland, Wales and Northern Ireland offices with a new department in charge of managing constitutional affairs and relationships between the governments.

In a report published today, the SAC says most key business is conducted between Scottish Government and Whitehall departments, bypassing Mundell’s team altogether – meaning a new system could work better.

According to the report, “it is unclear to us how much value it adds” to the day-to-day running of the UK’s political framework. And, highlighting “deteriorating levels of trust” between London and Edinburgh, it says urgent work is needed to repair relationships “at a time when goodwill and cooperation are needed most”.

This means beefing up the Joint Ministerial Council to provide a “robust” forum to handle governments that disagree on fundamental issues, devolution training for London-based civil servants and the publication of special impact assessments to show how policies will effect devolved governments, it is claimed.

SAC chairman Pete Wishart said: “It’s been 20 years since devolution and the political landscape of the UK is now totally unrecognisable; the Scottish Independence Referendum, Brexit and the diverging political views of the UK’s four governments have all placed strain on a delicate devolution system.

“The relationship between the UK and Scottish governments has broken down and there is a palpable lack of trust between the two governments.

“Although the relationship is far from ideal, it is not beyond repair. We are calling on the Scottish and UK Governments to make fundamental changes in their approach to devolution to restore trust.

“We’ve also heard evidence questioning the effectiveness of the Scotland Office in Whitehall, so we are pressing for a review of the role of the Scotland Office and the Secretary of State for Scotland to ensure intergovernmental processes adapt to the changing nature of devolution.”

The National asked Scotland Secretary Mundell and the Scotland Office to comment. In response, a UK Government spokesman said: “The role of the Secretary of State for Scotland is to champion Scottish interests at the heart of government and to strengthen Scotland’s place in the UK. With the Scottish Government proposing an unwanted and divisive second independence referendum next year, that role is more important than ever.

“Scotland’s two governments enjoy a close working relationship, as the Secretary of State’s evidence to the committee showed. We are pleased the committee acknowledged our joint efforts to develop common frameworks in areas such as agriculture when we leave the EU, which will strengthen the UK’s internal market.

“It is simply untrue to say that relations between the two governments have broken down.”

During evidence sessions, the SAC’s inquiry heard the “polarised politics” of the UK and Scottish governments “became particularly evident” during the 2014 independence. The report says the “trend of strained personal relations and lost trust between political leaders” has been made worse by Brexit.