Updated

Scotland's leader is warning British Prime Minister Theresa May not to block a referendum on Scottish independence.

First Minister Nicola Sturgeon says she intends to ask voters in late 2018 or early 2019 whether they want to leave the United Kingdom.

Britain decided in a 2016 referendum to leave the European Union, but Scots voted strongly to remain.

The British government must agree to a legally binding referendum. May has condemned the referendum call, accusing Sturgeon of sowing uncertainty and division.

Sturgeon tweeted Tuesday that she was elected "on a clear manifesto commitment" to hold a referendum. She added: "The PM is not yet elected by anyone."

May took office through an internal Conservative Party process after predecessor David Cameron resigned. Critics accuse her of lacking a strong popular mandate.