Then the northern lands grew restive. They wanted to govern themselves. A referendum was set for Sept. 18 on a simple question: Should Scotland be an independent country?

For two years, the kingdom's political leaders had treated their countrymen's threats to leave as an amusing sideshow, as poll after poll showed the status quo in a comfortable lead.

And then one day — this past Sunday, actually — they woke to realize that it had all gone a bit tatties o'wer the side.

The most printable translation of that Scottish term is: we're screwed.

In one week, Britain faces arguably the greatest constitutional question in its history, and the polls are too close to call.

For the first time since the referendum date was set in March 2013, a poll this past weekend showed the Yes (meaning, pro-independence) campaign with a 51 percent lead.

On Wednesday night, the union side was back in front with 53 percent, said Peter Kellner, president of the polling firm YouGov.