The Victorian sage and essayist Walter Bagehot once explained Britain's unusual constitutional arrangement as consisting of a "dignified" aristocratic branch, which mainly existed for show, and an "efficient" branch of professional politicians, who did the real governing. Britain's figurehead monarchs, he said, should offer advice and counsel and nothing more to the politicians governing in their name.
But the political fight over Brexit, Britain's pending exit from the European Union, risks blurring the demarcation, say royal advisers and the country's top civil servants.
They worry Queen Elizabeth II may end up in the middle of the toxic and polarizing political struggle over whether Britain should leave the EU, wrecking an unwritten constitutional arrangement that has evolved over centuries and kept sovereigns above partisan politics.
The monarch has privately expressed dismay with the quality of her country's current crop of politicians and their "inability to govern correctly," according to newspaper reports.
The Sunday Times reported the 93-year-old queen made her views known at a private dinner shortly after the 2016 Brexit referendum. Her exasperation reportedly has only grown since the polarization of the country over the issue, which risks breaking up the union of Great Britain.
Opinion polls suggest a majority of Scots now favor Scotland becoming an independent state and would vote to break away if a plebiscite were held.
Queens wants stability
The queen, who has reigned for 67 years, rarely comments even in private on party politics, and normally focuses any remarks more on the personal foibles of her prime ministers. Her comments are shared only within a very tight circle of relatives and trusted courtiers, a former aide, who spoke on the condition of anonymity, told VOA.
The queen prizes political stability and predictability "above all else," the former aide said, and was frustrated with Prime Minister Margaret Thatcher in the 1980s during a violent confrontation between her government and the country's coal miners, who shut down the British coal industry in a bid to prevent the closure of mines and their associated buildings and equipment.
Britain's new Conservative prime minister, Boris Johnson, has pledged to lead Britain out of the EU on Oct. 31 - a Brexit deadline agreed to earlier this year with Brussels.
Johnson said he'll leave the EU, regardless of whether he has struck a new withdrawal agreement with negotiators to replace the one secured by his predecessor. The parliament, deadlocked between pro-EU and euroskeptic factions, declined three times to endorse the exit deal May negotiated, dooming her leadership.
The Conservatives are ruling as a minority government and depend on a quirky and easily offended Northern Ireland Unionist Party to give them a working majority of just one in the House of Commons.
Pro-EU Conservative rebels, led by the outgoing chancellor of the exchequer, Philip Hammond, are making it clear that if Johnson tries to take Britain out of the EU without an exit deal, they'll side with opposition parties to bring down the government in a vote of no confidence.
That would either trigger a snap election or lead to an alternative government being formed. And that is where the danger lurks for the queen.
Johnson's aides say he would refuse to quit were he to lose a House of Commons confidence vote, defying convention, which would lead Britain into a constitutional crisis, one at least as unsettling as the abdication crisis of 1936, when Edward VIII was forced to relinquish the throne because he wanted to marry Wallis Simpson, an American divorcee.
Under the terms of modernizing legislation passed before the Brexit crisis, if a prime minister loses a full-fledged confidence vote, there is a 14-day period for a new government to form, one able to command a House of Commons majority. If a new government cannot be formed, a snap election has to be held. The legislation, however, isn't clear on whether Johnson would have to resign during those two weeks. Also not clear is what the political mechanism would be for the formation of a new government, as the legislation leaves it up to lawmakers to sort out.
Johnson's top aides say that if he loses a parliamentary confidence vote that opposition parties have threatened to call next month, he would remain at Downing Street and set an election date for some time after Oct. 31, his deadline for Britain to exit the EU. He would then contest an election on the question of "parliament versus the people."
Members of the main opposition Labor Party say they will tell Buckingham Palace they're ready to assume power and can govern like the Conservatives are doing now as a minority government.
Party leaders will call on the queen to ask their leader, Jeremy Corbyn, to form a government. Last week, their deputy leader, John McDonnell, said he'd send Corbyn to the palace "in a cab" to tell the monarch they were "taking over."
The queen last appointed a prime minister during political turmoil in 1957, when then-Prime Minister Anthony Eden resigned in the wake of the Suez Crisis. She asked Harold Macmillan to form a government, overlooking a more talented Conservative politician, R.A. Butler. Macmillan subsequently lost a general election to Labor.
Johnson's top aide, Dominic Cummings, told colleagues last week that Johnson would refuse to step aside if lawmakers voted to bring down the government. Some constitutional experts say Johnson would be under no legal obligation to resign. Others say it could lead to the queen being forced to remove the prime minister herself.
High-ranking Conservative Malcolm Rifkind, who served in Thatcher's Cabinet, last week warned that if Johnson remained at Downing Street, Johnson would trigger the "gravest" constitutional crisis since England's 17th century civil war.
"If the prime minister refused to respect the normal consequence of losing a confidence vote, and if he sought to prevent both parliament and the electorate having a final say on no deal, he would create the gravest constitutional crisis since the actions of Charles I led to the civil war," he said.
Former Conservative Attorney General Dominic Grieve has said, "The queen might have to dispense with his (Johnson's) services herself."
Johnson has cut a resolute figure since taking office - ignoring pressure from pro-EU Conservative rebels. His supporters say a no-confidence vote would be a last-minute desperate attempt to stop a no-deal Brexit taking place and to thwart Britain leaving the EU altogether, which a majority of Britons voted for in the 2016 Brexit referendum.
Labor's threat to inform the queen that they will form a new government has sparked the fury of Conservative Brexiters. Historian David Starkey said it would amount to a "coup." Former Conservative leader Iain Duncan Smith said Labor doesn't "believe in her or the Constitution."
The Times newspaper has reported that top civil servants and the queen's advisers have been meeting to discuss how to keep the monarch out of the raging partisan politics.