The question of 'whether Boris Johnson will survive as prime minister and for how long' has moved on to a more fundamental debate — whether Britain as we know it can survive his leadership. This week, a threat to the United Kingdom arose in the face of potentially breakaway moves from two of the four provinces that make up the country.

The ruling Scottish National Party (SNP) has announced a new movement to seek independence. And a new warning to Johnson from the majority parties in Northern Ireland has raised the spectre of a new breakaway push in the territory that the British government in London has long struggled to hold on. Scotland, Northern Ireland, Wales, and England are the four provinces that make up Britain.

Scotland was joined to Britain under a treaty concluded on May 1, 1707, following agreements passed by parliaments in Scotland and England. The Scottish Parliament is now headed the other way out.

The threat from Scotland is direct and immediate. First Minister of Scotland Nicola Sturgeon said Monday that the pro-independence majority in the Scottish Parliament following the elections in May mean that the SNP now has an "indisputable democratic mandate" to call another referendum. "We need to honour that," she told the media, and she has promised to do so by next year.

"After everything that has happened, Brexit, COVID, Boris Johnson, it is time to set out a different and better vision," she said. "It is time to talk about making Scotland wealthier and fairer. It is time to talk about independence and then make that choice." Her party wants Scotland to become an independent nation and then a member of the European Union.

The party lost its move for independence in a referendum in 2014 when 55 percent voted to stay on as a part of Britain. At that time, Britain was a member of the European Union. Since then, and since Brexit, the position has changed hugely. Rising prices and scarcity of goods have convinced many Scots that they would be better off within the EU than within the UK.

"In their day-to-day lives, people across Scotland are suffering the impacts of the soaring cost of living, low growth and increasing inequality, constrained public finances, and the many implications of a Brexit we did not vote for," Sturgeon said. "These problems have all been made worse or, most obviously in the case of Brexit, directly caused by the fact we are not independent."

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Sturgeon is due to unveil a list of campaigns seeking to demonstrate to Scots that they would be better off as an independent nation within the EU than as a province of the United Kingdom. The increasing unpopularity of Boris Johnson appears to be strengthening her campaign.

Northern Ireland

Challenges to the London government have arisen in parallel in Northern Ireland, British territory carved contentiously out of Ireland. Northern Ireland, traditionally the province of Ulster in Ireland, is sharply divided among Protestant Christians, who want union with Britain, and Catholic Republicans, who want Northern Ireland to become a part of the Republic of Ireland.

That deeply underlying split made Brexit dangerous. Britain entered into an agreement with the European Union over the movement of goods through Ireland that it has now announced it is stepping substantially away from.

That agreement became necessary because free movement of goods could no longer be possible after Northern Ireland was no longer a part of the EU. That set up a border with Ireland. To avoid a hard border, it was agreed that goods moving from Britain would be taxed in Britain so that no physical checks were needed between Ireland and Northern Ireland. Those would set off Republican-Unionist differences within Northern Ireland that could be politically explosive.

Several British leaders have condemned this move; it means that Britain is announcing that its word on international agreements cannot be trusted. It also amounts to an admission that the EU outsmarted Britain through the negotiations that led to that agreement, or at least that it had not thought through what it signed up to and now finds it cannot stand by.

Britain has proposed a new green channel to move goods from Britain to Northern Ireland. The EU says this violates their international agreement and has threatened to go to court. But it's not clear which court — the UK has also begun to challenge the European Court's jurisdiction that it had accepted earlier.

Catholic Republicans remain far more supportive of the EU than they are of Britain. Fifty-two of the 90 members of the Northern Ireland Assembly from Sinn Fein and other Republican groups have written to Boris Johnson to say that they "reject in the strongest possible terms your government's reckless new protocol legislation." That could now trigger far more severe confrontation to follow.

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— London Eye is a weekly column by CNBC-TV18's Sanjay Suri, which gives a peek at business-as-unusual from London and around.

Read his other columns here.