THE messages were always left when Henry Milner was out.

And they always more or less said the same thing: "Traitor".

"I had a wonderful tape of threatening calls," the Montreal activist-turned-academic remembers. "They never spoke to me, They would only say something if the answering machine picked up. Police said that as long as they were putting messages on tape they weren't the ones to worry about."

Milner's crime? Being an Anglophone Jew who backed independence for Canada's largely French-speaking province of Quebec. It was the 1980s he was a rare voice in his city's minority community who sided with the sovereigntist Parti Quebecois or PQ. "There certainly was divisiveness," the University of Montreal political scientist said. "'You traitor,' they would say.'How can you eve talk to these terrible people?" What terrible people? The PQ.

For much of the 1980s, including the first referendum on "sovereignty-association" for Quebec held in 1980, Milner was the English-speaking face of the movement, helping to organise visits to synagogues and other venues. His aim? Not so much to get Anglophones to vote Yes, but to ease hostility to a nationalist but social-democratic independence project that many non-French speakers, despite PQ protests of its inclusiveness, found threatening.

Scroll forward a decade, to 1995, and Quebec was voting on independence again, or "sovereignty-partnership" to use of the day. The province once again voted No, but only by 50,000 votes. The only place to ever reject its own independence at the ballot box. And it did it twice.

PQ leader Jacques Parizeau, in clear despair, lashed out, blaming "money and the ethnic vote". Milner, already semi-detached from the movement, was horrified. "'Oh God,' I said to myself. 'All that work in one statement was thrown away. We are going to have to start from zero."

The PQ has never quite won the confidence of Quebec's Anglophones, its English-speaking minority, and Allophones, those who speak a third language. A poll earlier this year found that half of all "English" Quebecers, a category that includes Scots, had considered leaving the province over the previous 12 months. The PQ - at the mere hint of another referendum - was hammered in provincial elections, recording its worst result since 1970. Support for independence, up at nearly half in 1995, runs at just 37% and next to nothing among English-speakers.

Now Milner is watching Scotland. How are minorities here responding to the independence debate? Will the SNP and Yes Scotland suffer the same demographic challenge as the PQ in winning September's vote. Michael Rosie knows the answer. The director of the Institute of Governance at Edinburgh University has crunched numbers for the last three Scottish Social Attitudes (SSA) surveys, the biggest and most detailed look at public views on independence. His findings? Scotland's "English", those born in England, are resolutely opposed. But Scotland's other minorities, those born outside the UK, are about as in favour of a Yes vote as native Scots.

The numbers are for 2010, 2011 and 2012 so predate the current referendum campaign. But this is a comparison of general attitudes by ethnic group, not a precise prediction of the result. The headline figures: support for full independence in all three surveys averaged at 15% for those born in England; 27% for Scotland; 27% for Wales, Northern Ireland and the Republic of Ireland; and 26% for everywhere else.

Matt Diffley of Ipsos Mori, looking at data from his own polling, came up with similar relative results. From eight polls from 2012 to early 2014, he put support for Yes at 19% among those born in England, Wales or Northern Ireland; 36% among those from Scotland; exactly the same figure for Scottish residents born outside the British Isles. One scenario predicted by at least two recent polls: that the opposite to independence is so strong among the 500,000 people born elsewhere in the UK that they swing the vote to No. The SNP - determined to underline its civic nationalism - says it regards all Scottish residents as Scots and avoids even the hint of problems.

Contrast hostility from Canadian anglophones to this week's indyref stunt by a group called English For Yes. They took to Scotland's streets with a Anglo-Saxon weapon: cake. Amid shrill headlines in Fleet Street tabloids of an anti-English edge to the independence movement, they sought to prove the inclusiveness of Yes.

The PQ would like to do the same. But Milner isn't entirely convinced that his former party has got its minority politics right.

PQ founder, Rene Levesque, a great believer in what he saw as a social democratic, inclusive project, signed a campaign poster for Mr Milner. He wrote, in English, "All Quebecers together".

Milner said: "Every corner of Levesque's body was civic nationalist. He did not have any sympathy for the chauvinist kind of nationalism." Milner is careful to say that the party today isn't bigoted. But he believes it is "insensitive" to how some of its policies, not least a controversial proposed Charter of Values, which included a ban on public employees wearing Muslim headscarves, would be seen by minorities.

"You have to be more than just staying away from bigotry," he said. "People from minorities are sensitive to certain expressions. You have to go out of your way to make sure you don't use them. I would never have been with the PQ if I thought they were like that. The current leadership were insensitive to how the Charter of Values could be interpreted that way. It was a sin of omission rather than Commission."

Michael Keating, professor of politics at Aberdeen University, isn't surprised to see the PQ struggle with the minority vote while the SNP does well. He compared with Charter of Values with policies on headscarves in France and Michael Gove's recent calls for "British values" to be taught in schools. He said: "The PQ has never been very big on multi-culturalism, they take a more French attitude. It appeared to be a attempt to appeal to a core vote. It's completely different for the SNP. They have never tried to essentialise Scottish nationalism in this way and, in fact, have made a concerted effort to appeal to the ethnic vote. There is an electoral case for them to do this. But it is also a form of legitimisation, proving their conviction that they are not ethnic nationalists."

Milner isn't the only one-time independence sympathiser disappointed with what he sees as a "cynical electoral ploy" by the PQ to use the Charter of Values to deliver a conservative, rural, Francophone vote, away from cosmopolitan Montreal.

This upsets Bernard Drainville, the PQ deputy, as a minister in the party's minority administration that crashed out of power in April, was responsible for steering the Charter through Quebec's National Assembly. His view: that the Charter was designed to ensure the religious neutrality of the state, especially in a Quebec dominated until the 1960s by the Catholic Church.

Speaking exclusively to the Sunday Herald, he said: "The opposition said that the Charter was a xenophobic, anti-immigration posture. They exploited it. Quebec is an increasingly multi-ethnic and multi-religious society, which is a great thing. It's a formidable richness, diversity is strength."

"But you also need to identify what you are common values are. We thought and I still believe in is that the best way do protect everyone's religion - and everyone's right to have or not to have a religion is to have a completely neutral state. That state in return can be like the common ground where everyone can gather as a citizen, not as a religious person."