Sep 16, 2014 3 min read

LONDON – With two days of fevered campaigning left before Scotland votes in a referendum on independence, the leaders of the three main British political parties renewed a pledge on Tuesday to grant Scots “extensive new powers” if they reject secession.

But proponents of independence seized on the pledge’s lack of specifics and on the recent differences among the three party leaders in their approach to the Scottish question to dismiss the appeal as empty rhetoric.

The renewed pledge came in a letter published in The Daily Record on Tuesday. The day before, Prime Minister David Cameron of Britain offered Scots a different message, telling them bluntly that “independence would not be a trial separation” and that if the “yes” vote prevails on Thursday, “there’s no going back from this, no rerun.”

The combination of warning and promise reflected the deepening concerns among the political elite in London that the pro-independence campaign was gathering momentum. As the vote approaches, both sides have been striving to win over undecided voters, in what has become a collision of visions.

While those in favor of independence depict a sovereign Scotland as a wealthy place of opportunity and renewal, those opposed talk of the harm the breakup might do to jobs, prosperity and stability. The anti-independence former Prime Minister Gordon Brown, himself Scottish-born, said on Tuesday that separation from the rest of Britain would be a “messy and expensive and costly and difficult divorce.”

“The effect of Sept. 18, if you vote yes, is to end every single last remaining link that exists, the connections we have, with our friends, neighbors and relatives,” Brown said.

But Nicola Sturgeon, Scotland’s pro-independence deputy first minister, said an independent Scotland would “continue to be part of the family of nations that make up the British Isles,” and added, “We will work closely and cooperatively with our friends across these islands, but we’ll do so on the basis of equality, we’ll do so knowing that we’re responsible for the decisions that shape our future.”

The wide lead that the “no” side had in early opinion polls has appeared to narrow in recent weeks, to the point that the outcome has become too close to call. One survey earlier this month even found the “yes” campaign, led by Scotland’s first minister, Alex Salmond, slightly ahead. That prompted the political elite in London to promise Scotland wider autonomy if voters reject independence.