A PRO-independence party seeking a second referendum becomes the official opposition in the House of Commons amid economic turmoil which ended two terms of majority conservative government.

That would be the astonishing outcome of a UK General Election if one were held today, according to current polling.

It’s a scenario that one SNP MP simply laughed off when I raised it with them this week, but one taken seriously enough by Conservatives to mean there won’t be an election anytime soon.

“If there was a General Election tomorrow, which of course there won’t be, we’d be a smaller party than the SNP,” Conservative MP Sir Charles Walker told the BBC this week.

And they might well take such a humbling prospect seriously because, as unlikely as it seems, there is precedent for exactly that scenario.

Back in October 1993, the Bloc Quebecois became the official opposition in the Canadian parliament’s lower house, also known as the House of Commons, after a watershed election in which the Progressive Conservative Party were swept from office after nine years in power amid discontent among voters of their handling of a global economic downturn.

The Bloc had been formed just two years earlier to represent Quebec’s interests at federal level by formerly conservative MPs in response to the failure to deliver on constitutional reform known as the Meech Lake Accord which would have handed greater autonomy to Quebec.

READ MORE: BBC 'block' Alba advert as party decry 'democratic deficit'

Winning half of the vote in Quebec and 54 of Canada’s 295 seats in their first electoral test, the Bloc’s influence was increased by the emergence of another new party, Reform, which further splintered conservative support and left the Bloc as the second largest force in the Commons.

What happened next gives as close an insight as is possible to gain on how such a scenario could play out in the UK – and it’s one that might provide some reassurance for those south of the Border.

“I think people outside Quebec found the situation weird and anomalous,” Professor David Cameron of the University of Toronto told The National. “But fairly quickly, as I recall, there was an adjustment to the new reality.

“The Bloc did not seek to disrupt Parliament or bring its business to a grinding halt.”

The current month, and talk of Quebec nationalists, might bring to the minds of many Canadians the “October crisis” of 1970, during which the country’s prime minister Pierre Trudeau had sent the military on to the streets of Quebec in response to the kidnapping and murder of a federal government minister by the extremist Front de liberation du Quebec.

The Bloc’s founder and leader, Lucien Bouchard, couldn’t have been further removed from that image.

A former lawyer, Canadian ambassador to France and federal environment minister, Bouchard was an establishment figure who was already well known and respected outside of Quebec.

And he immediately went out of his way to settle nerves in English-speaking Canada.

With a neat side parting, a conservative dark blue suit and pointedly speaking in measured English, he cut a reassuring figure at a post-election press conference in which he told journalists: “I think it’s not possible to pave the road to sovereignty in raising hell.”

When the Canadian parliament reconvened in January 1994, Bouchard didn’t mention Quebec once in his first appearance as leader of the opposition.

Instead, he dedicated all three of the questions afforded to the leader of the opposition in the Canadian House of Commons to scrutinising the Liberal government’s plans to reduce the country’s fiscal deficit through cuts to social spending.

One of the biggest questions stemming from the scenario set out in current UK polls is what approach an SNP opposition would take to non-devolved issues.

In the case of Canada, the Bloc “examined legislation not relevant to Quebec through an ideological lens, that of the centre-left,” said Professor Andre Lecours, an expert on nationalism in both Quebec and Scotland from the University of Ottawa.

READ MORE: Protest planned for Glasgow as Rishi Sunak to become prime minister

Even if the Liberal government were facing a party that had no desire to replace them, “the Bloc were an excellent official opposition,” said Lecours. “And that comes from someone who has never voted for the Bloc.

“The party obviously criticised Canadian federalism at every opportunity but it never sought to disrupt or sabotage the functioning of the Canadian federation.”

But however disarming and constructive Bouchard may have been in the Canadian capital of Ottawa, his role as leader of the federal opposition gave him an unrivalled platform to campaign for independence from it.

He is credited with turning around the fortunes of the Yes campaign during Quebec’s second independence referendum in 1995.

“The shift in momentum this time around was caused primarily by the decision of Quebec premier Jacques Parizeau to turn over principal leadership of the flagging Yes side to Lucien Bouchard, leader of the separatist party in the federal parliament,” reported the Washington Post at the time.

The leader of the Canadian opposition took the Yes campaign within 55,000 votes of victory – but the referendum nonetheless ended in a second defeat, the consequences of which are still playing out today.

Bouchard went on to replace Parizeau as the Parti Quebecois premier of Quebec.

But three decades after his federal breakthrough, independence barely figured as an issue in the Quebec elections earlier this month and, bringing history full circle, the Parti Quebecois has been usurped as the country’s dominant political force by a conservative split from it founded by one of Bouchard’s own former ministers.

A cautionary tale as much for the SNP, then, as for the Conservative Party.