GLASGOW — The annual Scottish National Party conference used to be a marginal affair in British politics. With few observers save the local press, battle-hardened activists would meet in a provincial Scottish town hotel to debate local issues.

This year is different.

On Thursday, under the watchful eye of international journalists, thousands of SNP delegates will gather at a towering conference center on the banks of Glasgow’s River Clyde to debate two existential questions: the meaning of Brexit for Scotland and the possibility of a second independence referendum.

What happens in Glasgow will do much to set the tone for the coming months — not just in Scotland but in the rest of the U.K., too.

First Minister of Scotland and SNP Leader Nicola Sturgeon’s keynote speech on Saturday is sure to be closely watched, as is the election of a new deputy leader, a role that indicates the future direction of the party. And a motion calling for the Scottish government to prepare a second independence referendum — "if no viable solution to safeguard our membership as part of the U.K. exists" ­— is likely to fuel a lively debate on the floor.

Even within the Scottish National Party, there are fault lines when it comes to independence — and Brexit has laid them bare.

Sturgeon and her Brexit minister, Michael Russell, have made it clear they want to retain Scotland’s place in the EU. But others see opportunities in the U.K.’s vote to leave the European Union.

Veteran nationalist Alex Neil, a former cabinet minister, has argued Brexit is a “golden opportunity” for the Scottish government to assert control over farming, fishing, employment law and other areas currently decided in Brussels. “Neo-independence” will provide the “ideal platform” for full independence in the 2020s, Neil has argued.

The decision on a second referendum will come down to the SNP’s power couple: Nicola Sturgeon and her husband, party chief executive Peter Murrell.

Meanwhile, former Justice Minister Kenny MacAskill has criticized the “timidity” of Sturgeon’s government, arguing that “the danger is that her government end up simply managing, not leading, the political agenda.”

But ultimately, the decision on a second referendum will come down to the SNP’s power couple: Sturgeon and her husband, party Chief Executive Peter Murrell. The pair controls the central levers of power in the SNP and few dissent from their leader.

Lately, however, observers have noted signs of more openness within the SNP, paradoxically brought about by Brexit. The conference will do much to reveal how open Sturgeon really is to alternative views.

“Politics now is very different to what it was in 2014,” says Andrew Tickell, a lecturer of law and a columnist for the Times.

Toxic rhetoric

Two years ago, Scottish voters rejected independence in a closely watched referendum, prompting Alex Salmond, the Scottish first minister and then-leader of the SNP, to step down.

In the weeks after, independent-minded Scots joined the “yes” parties — the SNP, the Scottish Green Party and the Scottish Socialist Party, and today SNP membership is at an all-time high at 125,000.

But two years of existential tumult has taken its toll. And earlier this year, Scottish politicians looked set to return to bread-and-butter issues. When the SNP won its third consecutive term in the devolved government in Edinburgh in May, the manifesto promised that another referendum would only be held if there were “significant and material” changes to Scotland’s circumstances.

As May has made clear her intention to pursue a so-called “hard Brexit,” the Scottish leader has shown a more pugilistic side.

The Brexit vote in June changed everything.

On the morning of the result, Sturgeon declared that a second independence referendum was “highly likely” given that a majority of Scots had voted to stay within the European Union.

Aware the Scots were restive, the new British prime minister, Theresa May, made Edinburgh her first port of call in July, extolling the virtues of the “special union” between England and Scotland.

At first, Sturgeon appeared to temper talk of another referendum as polls showed little increase in the appetite for independence. But in recent weeks, as May has made clear her intention to pursue a so-called “hard Brexit,” the Scottish leader has shown a more pugilistic side.

Sturgeon castigated May on Twitter and has publicly condemned the U.K. government’s “toxic rhetoric on immigration.” May, in turn, seemed to fire a shot across the Scottish bow at the recent Conservative Party conference in Birmingham, telling Tory delegates — to wild applause — that she would “never allow divisive nationalists to undermine the precious union,” pledging there would be no Scottish “opt out” from Brexit.

In addition to navigating Brexit and devising a strategy for independence, there is the struggling economy and the global downturn of oil prices to consider.

When the SNP delegates meet this week, the prime minister’s bellicose words will be ringing in their ears. Such language does little to mend Anglo-Scottish relations and almost certainly weakens the union in the long run. In the short-term, too, May has put Sturgeon in a bind: Should Sturgeon call a referendum now and risk losing what might be her one shot at independence? Or should she wait for a better opportunity that might never appear?

“One of the arguments for waiting is we still don’t know what Brexit means,” says Tickell.

While some in the party, like Tickell, favor a wait-and-see approach, many grassroots activists are hoping the SNP leader will use her keynote speech on Saturday to push independence — and fast, by calling a second referendum.

“Now Nicola Sturgeon has to call it,” says Suzanne McLaughlin, a former SNP candidate and owner of the pro-independence “Yes Bar” in central Glasgow. “You can sit forever and say ‘when will be the right time?’ 2014 was a leap of faith and we almost got there. Now with Brexit and the racist rhetoric, it would be more morally reprehensible if we didn’t [hold another referendum]."

So far, the Scottish first minister has kept her counsel.

Brexit clarity

Another question to be settled this week is the appointment of SNP’s deputy leader, a symbolically important role that’s been held by the SNP’s last five leaders — including Sturgeon.

The four-way contest is seen as something of a battle for the direction of the party.

Moray MP Angus Robertson is widely considered the favorite to win the appointment. The 47-year-old leader of the SNP group in the House of Commons — where the nationalists hold 54 of Scotland’s 59 seats — is seen as a standard-bearer of the nationalist establishment. (He reportedly joined the party aged 15 after being handed a leaflet by Charlie Reid, singer in pop group The Proclaimers).

One joker in the pack, though, is the new mass membership of the SNP. Almost overnight in the wake of the September 2014 defeat, the party quadrupled in size and it has since continued to climb. The voting intentions of the new members are hard to gauge but one favored candidate could be MP Tommy Sheppard, who is more volubly in favor of party reform than Robertson.

Sheppard, a former assistant general secretary of Scottish Labour, who joined in 2014, has promised greater distribution of power in what remains a very hierarchical party. (Separately, a motion calling for the strengthening of internal party discipline is on the conference agenda).

Also in the running for the deputy leadership is local councilor Chris McEleny and the experienced Brussels hand, Alyn Smith. The Scottish MEP’s pitch has focused on his insider knowledge of the European Union at a crucial time for Edinburgh’s external relations

Whoever wins the contest, Scotland’s leaders will have a lot on their plate. In addition to navigating Brexit and devising a strategy for independence, there is the struggling economy and the global downturn of oil prices to consider.

“Scotland exports more than 60 percent of its good to England. This fact cannot be straightforwardly cauterized,” says Tickell. “Scotland facing a hard Brexit makes another referendum harder. But, on the other hand, it does clarify the issues.”