LONDON — British Prime Minister David Cameron waded forcefully into the debate over Scottish independence on Friday, delivering an impassioned call to keep the United Kingdom together just seven months before Scots vote on whether to break up the three-century-old union.
On political, economic, and military grounds, Cameron argued, Scotland is better off as a part of Great Britain. But Cameron also made an unusually emotional appeal, invoking Scotch whisky, the Sherlock Holmes franchise, and the British Olympics squad as examples of successful collaborations that would be diminished by a split.
‘‘This is our home — and I could not bear to see that home torn apart,’’ Cameron said. ‘‘I love this country. I love the United Kingdom and all it stands for. And I will fight with all I have to keep us together.’’
Polls suggest that most Scots agree that they should stick with their southern neighbors, and that Scotland will opt to remain a part of Great Britain in the Sept. 18 vote. But opinions remain fluid, and some surveys show those favoring independence gaining ground as the debate heats up.
Friday’s speech was politically treacherous for the prime minister. Cameron, and the Conservative Party he leads, are not popular in Scotland, which tilts left politically. He badly needs to keep the United Kingdom from coming unglued under his watch, but he also risks alienating Scottish voters if he becomes the face of those campaigning for a ‘‘no’’ vote on independence.
His intervention could be perceived as just the sort of English imperiousness that the Scots are seeking to escape.
‘‘It’s a tightrope,’’ said Nicola McEwen, who teaches politics at the University of Edinburgh. ‘‘If it becomes the British government versus the Scottish government, that plays into the hands of the independence movement.’’
The leader of the Scottish independence drive, Alex Salmond, has repeatedly challenged Cameron to a debate. On Friday, after Cameron spoke, he renewed that push. ‘‘Let’s have that debate, instead of having a sermon from Mount Olympus,’’ Salmond told the BBC.
Other Scottish independence leaders accused Cameron of cowardice for giving the speech at the Olympic Park in London, rather than in Scotland.
Cameron has insisted that the choice in September is one the Scots must make themselves, and that they should be the primary players in any debate.