Prime Minister David Cameron made a final plea to Scotland’s voters, urging them to step back from an illusory “dream” of risk-free independence and avoid the irreversible breakup that would come with a “yes” vote.

In a speech in Aberdeen today during his last visit to Scotland before the Sept. 18 referendum, Cameron promised a “major program” of change, saying the campaign has “swept away” the status quo. Guaranteeing unprecedented powers if voters opt for “no” in three days, he appealed to Scots not to walk away from the economic security, shared history and achievements of the 307-year-old union.

“It would not be a trial separation. It would be a painful divorce,” Cameron said. “I don’t want the people of Scotland to be sold a dream that disappears.”

European governments are looking on as campaigning nears its climax, with polls suggesting the Better Together campaign has failed to quash the pro-independence push led by Alex Salmond, leaving the outcome on a knife edge.

As London hosted a rally late today in favor of the union and a “no” vote, Cameron made his second trip to Scotland in a week to try and prevent one of the biggest redrawings of the political map of western Europe since World War II.

Mortgages, Pensions

The prime minister listed the risks of independence, from pension funds being “sliced up” to the loss of embassy support worldwide and mortgages held by banks in what would be a foreign country. He also offered the prospect of his own political mortality as an inducement, saying that while he and his government “won’t last forever,” a split from the U.K. would be a “once-and-for-all decision.”

In an effort to distance himself from the charge of negative campaigning that has plagued Better Together, Cameron made repeated references to Scotland and the U.K. as a “family” with shared values and accomplishments.

Cameron said he understood why some people would vote “yes,” drawn by the “promise of something different,” whereas in reality Salmond’s nationalists were painting a false picture of the future independence would bring.

“When something looks too good to be true –- that’s usually because it is,” he said. “Head and heart and soul, we want you to stay.”

Politicians and activists are fanning out across Scotland in the final countdown to the ballot, with both the “yes” and “no” campaigns saying they’re poised to win. The pound dipped against the dollar and 10-year gilts edged up after weekend polls gave contradictory pictures of the outcome.

Blair Jenkins, the chief executive of the Yes Scotland campaign, dismissed the prime minister’s speech as “the same litany of empty threats and empty promises.”

“Only by voting ‘yes’ will Scotland always get the governments we vote for -- and never again Tory governments imposed by Westminster,” he said in an e-mailed statement.

To contact the reporter on this story: Svenja O’Donnell in Edinburgh at [email protected] To contact the editors responsible for this story: Alan Crawford at [email protected] Andrew Langley