Senior politicians from the SNP have speculated that Theresa May wants to postpone a second independence referendum until after Brexit, in part to prevent EU nationals from voting in it.
There are 183,000 EU nationals who were born outside the UK but who live in Scotland, and the SNP believes there has been an "enormous swing" within that group towards independence since the Brexit vote.
May's refusal to consent to another referendum on independence until after the UK leaves the EU could jeopardise their current voting rights, and SNP politicians have told BuzzFeed News that this would be "playing with Scottish democracy".
SNP deputy leader Angus Robertson said he believes May is trying to push back a referendum "for as long as possible", to a point in time where EU citizens may no longer be able to vote.
"To pull Scotland out of the EU with the rest of the UK, and then as a result disenfranchise EU citizens in Scotland from being able to exercise a choice which the rest of us might then be able to have at some future date, is playing with Scottish democracy," said Robertson.
The SNP's Europe spokesperson Stephen Gethins MP, when asked if he fears EU nationals might be disenfranchised, said: "You can understand why there’s significant concerns by European nationals who have made Scotland their home.
"The UK government has refused to give them certainty and give them right to remain. We believe this is their home and they should be able to vote. They’re part of the fabric of Scottish society just as everyone else is."
Christian Allard, a French-born former SNP MSP and candidate for the forthcoming local election, said: "A Tory prime minister didn't want me to vote in the referendum last year, this one doesn't want me to vote in #ScotRef, quelle surprise!"
The SNP conference backed a resolution on Friday morning which supported protecting the voting rights of EU citizens after Brexit, with one speaker, Douglas Daniel, accusing the UK government of attempting to "gerrymander" the franchise.
The Electoral Commission said that EU nationals can currently vote in Scottish and local elections, and that electorate – plus 16- and 17-year-olds – was used for the first referendum on independence.
The franchise for a second referendum would have to be agreed upon by the UK and Scottish governments, but it's unclear whether or not EU nationals will maintain current voting rights after the UK leaves the EU.
The Scotland director of polling company Ipsos-Mori told BuzzFeed News that increased support from EU nationals could potentially be significant, to the tune of one or two percentage points, in a further referendum on independence.
"It could put a point or two on it [the Yes vote]," said Mark Diffley. "If they were voting at 35% [in 2014] and you can get them to 50% that’s not enough to swing the referendum but they’re exactly the sort of group that the Yes side will be looking at.
"If you can establish it’s the Brexit process is making them feel differently, I’d say that’s gold for the Yes side in terms of how they win people over. But, by themselves, they’re not enough to put more than a point or two on."
Given May's determination to influence the timing of the next referendum, the SNP believes it's feasible she could insist the franchise of such a vote, like the EU referendum last year, excludes EU nationals.
Drew Hendry – the MP for Inverness, Nairn, Badenoch and Strathspey – told BuzzFeed News he believes there has been an "enormous swing" towards independence among the EU nationals he's encountered since last June.
"In 2014, I know from speaking to Polish nationals, I knocked on doors in my constituency, most of them bought the line which has now turned out to be a falsehood that if they voted No in the referendum they’d be allowed to stay working and living here inside the EU," said Hendry.
"Since the Brexit vote there’s been an enormous shift in attitude and some of them have to come to me offering their apologies for making the wrong choice. There’s an enormous swing to the other point of view now."
Hendry added: "If a consequence, intended or otherwise, of Theresa May trying to block that referendum is that it disenfranchised people in Scotland who are entitled, including EU nationals, that would be a further outrage to add to the outrage of telling the Scottish parliament what it can or can’t do."
The UK government's Scotland secretary was asked directly on Thursday whether the decision to delay another referendum on Scottish independence was made in an attempt to influence the ability of EU nationals to be able to vote.
"No, that’s not the basis on which this decision is being made," said Mundell. "I’ve set out the reasons we’re objecting this process – it’s because for all those concerned there would not be the possibility of a fair choice in the timescale envisaged.
"We want to resolve the issue of EU nationals in Scotland and the rest of the UK and I hope we will soon, now negotiations are formally beginning, we will be able to confirm all EU nationals in Scotland will be able to stay in Scotland."