OTTAWA -- The NDP's proposed "unity bill" has sparked some disunity in the party's own ranks.

One of the most prominent NDP stalwarts, former Saskatchewan premier Roy Romanow, says he disagrees with the federal party's proposition that a bare majority Yes vote would be sufficient to trigger negotiations on Quebec's secession from Canada.

And he says he's not the only New Democrat with qualms.

"I think within the party there are many people of varying views on this particular issue," Romanow told The Canadian Press.

"I think there's room in the party for a lot of debate and discussion about this issue, certainly when it comes to national unity. To me, it's probably one of the most important, if not the most important issue that any political party in a federation as diverse and fragile as ours must consider."

The NDP's unity bill is meant to replace the Clarity Act, passed by former Liberal prime minister Jean Chretien's government in 2000 following the country's near-death experience in the referendum on Quebec independence five years earlier.

The act stipulates that a clear majority of Quebecers would have to vote Yes on a clear referendum question before the federal government would agree to negotiate terms of a divorce.

It does not specify what constitutes a clear majority, allowing parliamentarians to take into account voter turnout, voting irregularities and other factors before concluding whether the result is sufficiently unambiguous to warrant negotiations.

Federal New Democrats supported the Clarity Act in 2000, as did Romanow, then Saskatchewan premier. The NDP has since changed its mind. Romanow has not.

Indeed, at a tribute for Chretien last month, Romanow told some 700 luminaries from multiple political parties that Clarity was "a great act of political vision and courage and determination" that he's proud to say he supported.

In a subsequent interview, Romanow stressed that he supports NDP Leader Tom Mulcair and understands why he has embraced the notion that 50 per cent plus one vote should be the threshold for any successful referendum vote.

"I can certainly understand the federal NDP's position," Romanow said.

"You have a principle here about democracy working and if 50 plus one is thought to be the general rule in a democratic society then ... that's exactly what should govern all decisions, including the decision with respect to a possible separation.

"That can't be dismissed easily, that argument."

Nevertheless, he added: "I just don't accept its consequences or its potential consequences."

Romanow said he and his government's legal and constitutional advisers did seriously consider whether a simple majority should be sufficient. But after analysing the Supreme Court's advice on the rules for secession, upon which the Clarity Act was based, they concluded that the fate of the country could not hinge on a judicial recount over a handful of votes.

Romanow said he continues to believe that "the nation called Canada ought not to be easily broken up by a clerical error or the wrong attendance of a wrong voter at the wrong time and the wrong place, or something of that nature, that there's got to be a clear expression of it."

Mulcair has called the Clarity Act "a fairy tale told by the Liberals," meant to persuade Canadians that any referendum result they don't like can be tossed out.

But Romanow said he believes the act accurately reflects the advice given by the Supreme Court.

While the top court did not specify a threshold, it did signal that something more than 50 plus one should be required. For instance, it referred repeatedly to the need for a "clear majority," said both the referendum question and the result must be "free of ambiguity" and noted that "Canadians have never accepted that ours is a system of simple majority rule."

The court said it would be up to political actors to determine the precise threshold, taking into account the circumstances surrounding any referendum vote.

The unity bill sets the threshold in advance but stipulates that a simple majority vote would trigger secession negotiations only if the referendum question was clear and there were no "determinative irregularities" in the vote.

The bill makes no allowance for voter turnout. Toronto MP Craig Scott, author of the bill, has said turnout is unlikely to be a problem, noting that 85 and 94 per cent of Quebecers voted in the 1980 and 1995 referendums respectively.

However, anything less than 100 per cent turnout would mean, under the NDP's bill, that less than half of Quebec's eligible voters could end up triggering the breakup of the country.

Romanow said it's those kinds of concerns that persuade him it is more prudent to set "a higher bar."

Scott was not available to comment on Romanow's views.