UK prime minister: 'There will be no opt-out for Brexit'

Pledging to make the United Kingdom "truly global," UK Prime Minister Theresa May revealed her plan Sunday to begin the process of separation from the European Union by March 2017. May told the Conservative Party conference she plans to trigger Article 50 of the Treaty of Lisbon, which sets the requirements of any country wishing to leave the EU.

"There will be no unnecessary delays in invoking Article 50," May said. "We will invoke it when we are ready. And we will be ready soon. We will invoke Article 50 no later than the end of March next year."

This declaration ushers in the process of negotiation, with May saying she's keen to get talks underway and considers border control a priority. This was met with a polite but firm rebuttal from the president of the European Council, Donald Tusk, who tweeted shortly afterward:

PM May's declaration brings welcome clarity on start of Brexit talks. Once Art. 50's triggered, EU27 will engage to safeguard its interests

— Donald Tusk (@eucopresident)October 2, 2016

Though it was denied by Downing Street, the prime minister appeared to suggest that she was seeking Britain's exit from the single market when she said that the UK would be a "fully independent, sovereign" country. One EU insider told the FT: "She seems to be saying that regaining sovereignty is so valuable [that] she is willing to pay a price in terms of economic disruption."

In a veiled reference to the Scottish National Party, May also insisted that Scotland would be leaving the EU along with the rest of the United Kingdom, saying: "There is no opt-out from Brexit. And I will never allow divisive nationalists to undermine the precious union between the four nations of our United Kingdom." This provoked an angry Nicola Sturgeon to tweet:

PM going out of her way to say Scotland's voice and interests don't matter. Strange approach from someone who wants to keep UK together.

— Nicola Sturgeon (@NicolaSturgeon)October 2, 2016

Scotland's Brexit minister Mike Russell went further, warning that unless Scottish interests are not raised in negotiations, Holyrood could block the Repeal bill. There was also concern from some Sinn Féin ministers on the implications for Northern Ireland.

After May's speech revealing the date for a UK exit from the EU, the pound fell to its lowest level against the dollar in three months. It also fell to a three-year low against the euro before rallying slightly.