Why Brexit Could Lead to Breakup of UK

LONDON— -- Brexit could now threaten the unity of the United Kingdom as Scotland and Northern Ireland raise the prospect of holding their own referendums to leave the U.K.

The option of an independence referendum for Scotland is "on the table,” Scottish First Minister Nicola Sturgeon said today, speaking shortly after results of a referendum signaled that the U.K. had voted to leave the European Union.

Across the U.K., the “Leave” side garnered 51.9 percent of the vote, while the “Remain” side garnered 48.1 percent, according to the U.K.'s Electoral Commission. Prime Minister David Cameron announced shortly after the results that he would resign by October.

As for Sturgeon, "This is not a situation that I wanted Scotland or the U.K. to be in today," she said.

Scotland was firmly in the “Remain” camp with 62 percent who voted to stay, against 38 percent for leaving the U.K. While Scots voted to remain in the U.K. in a 2014 referendum, Thursday’s vote could prompt them to at least call for another vote.

Sturgeon said it is "democratically unacceptable" for Scotland to be taken out of the E.U. and insisted she would take "all possible steps and explore all options.”

In Northern Ireland, where 56 percent voted to remain in the E.U., the Deputy First Minister Martin McGuinness has also called for a vote on a United Ireland.

In a statement, the Irish government said the result had "very significant implications for Ireland, as well as for Britain and for the European Union.”

Some have said that Spain could also seek co-sovereignty of Britain's small Mediterranean enclave of Gibraltar. The British Overseas Territory, ceded by Spain 300 years ago, voted 96 percent to stay in the E.U. and is wholly reliant on Spain for trade and access.

But Gibraltar's chief minister said they will never be part of Spain.

Meanwhile, London Mayor Sadiq Khan said in a statement that it was “crucial” for London to remain part of the EU’s single market.

"I will be pushing the government to ensure this is the cornerstone of the negotiations with the E.U.,” he said. “It is crucial that London has a voice at the table during those renegotiations, alongside Scotland and Northern Ireland.”