BORIS Johnson has been warned that he should only travel to Scotland if he has “some real work to do”. 

LibDem MP Alistair Carmichael said any day trip north of the border shouldn't be about photocalls. He also urged the Prime Minister to visit representatives of Scotland's beleagured fishing industry.

READ MORE:Boris Johnson reportedly coming to Scotland this week in bid to save union

The former Secretary of State for Scotland accused Johnson of treating his role as Minister for the Union "like a punchline."

The veteran LibDem said: "Ronald Reagan famously said that the scariest words in the English language were 'I am from the government and I am here to help you'.

"For those of us making the case against separation the Prime Minister making a day trip of this sort has a similar ring."

Currently, it’s against the law to travel from England into Scotland without a “reasonable excuse”.

The Prime Minister - and everyone else - can “travel for work” but “only where that cannot be done from your home.”

Carmichael said Johnson needed to heed the rules.

He said: "The current guidance is clear that people should not travel except for essential work. If the Prime Minister is intending to travel then he had better have a real reason and some real work to do - not just staged photoshoots.

"When the Prime Minister came to Scotland last summer, he posed for the cameras with Orkney crab and promised good times ahead. If he's determined to visit again, he should meet with those same producers to apologise for breaking his promises and wrecking their access to vital European markets.

"Bungling Boris Johnson has been consistently the most effective recruiting sergeant the nationalists could dream of.

"If he wants to change that perception then he could start by treating his title as Minister for the Union a little less like a punchline."

More details have emerged of what the Tory chief could be doing on his “all-out bid to save the United Kingdom”.

According to the Guardian, Johnson is set to announce “that he considers the UK’s existing constitutional architecture is not working.” 

The paper says he will unveil a “third way” approach somewhere between the status quo and independence

This will be “based on the principle of the UK adding value to the devolved settlement, as well as launching an all-UK strategy that could involve new and wider devolution and a more federal structure to the UK’s constitutional arrangements, potentially extending to reform of the House of Lords.”

Over the weekend, it was revealed that Michael Gove had met with Gordon Brown, who has long pushed for a review of devolution across the UK.

Reports suggested the two men talked about building the case for the Union.

Meanwhile, on Tuesday, Alun Evans, who was director of the UK Government’s Scotland Office between 2012-15, criticised Johnson for ruling out calls for another vote.

The National:

He also suggested that there should be a third option of “home rule” on any indyref2 ballot.

In a letter to The Times, the former civil servant also said independence should only happen if the Yes side won a 60% “super-majority”.

Evans said an SNP victory at May’s election would be an “existential threat” to the future of the UK.

He said: “The response from the Prime Minister to reject out of hand the idea of another referendum is the political equivalent of burying your head in the sand,” he added.

Over the weekend, SNP ministers said they would hold indyref2 even if Downing Street refused to grant a Section 30 order - the temporary transfer of powers that allows Holyrood to legislate on reserved issues.

Their new roadmap said it would ultimately be for the UK government to challenge the legitimacy of any vote in the courts. 

However yesterday, Douglas Ross, the Scottish Tory leader, said the Unionist side would simply not take part in a vote that didn’t have the approval of London. 

He said: “An unofficial referendum should be boycotted. It shouldn’t be given any credibility. It is again a divisive tactic by the SNP to split our country apart.”

READ MORE: Holyrood can use 'principle of self-determination' to override indyref2 veto

An SNP spokesperson said: “The Prime Minister is always welcome to visit Scotland. The law in Scotland requires all work that can be done at home, to be done at home and Scottish ministers are not engaging in visits in line with the current Stay at Home regulations and the requirement to stay local, so it's clear the PM must think the Union is really in peril if he considers his visit to be so essential."