Lawmakers in Scotland on Tuesday voted in support of holding a second referendum for the country’s independence from the United Kingdom, giving First Minister Nicola Sturgeon the go ahead to ask the British Parliament for a vote between 2018 and 2019. “This is...about giving the people of Scotland a choice on this country’s future,” Sturgeon said. “The mandate for a referendum is beyond question, and it would be democratically indefensible...to attempt to stand in the way of it,” CNN reported, quoting the Press Association.

Scottish parliamentarians voted 69-59 in favour of the move. Sturgeon’s Scottish National Party, which holds a majority in Parliament, was backed by the Green Party. The Labour Party, the Liberal Democrats and the Scottish Conservatives all opposed holding a referendum.

Sturgeon has stressed that the referendum should be held “no earlier than 18 months from now, when the terms of Brexit are clear”. The first minister has been fiercely advocating for Scottish independence since the UK voted in favour of the UK’s departure from the European Union in June 2016.

However, British Prime Minister Theresa May has said that “now is not the time” for a vote that could break up the UK. May has already signed the letter that will formally trigger the UK’s departure from the European Union under Article 50 of the Lisbon Treaty. The letter will be delivered to European Council President Donald Tusk on Wednesday, BBC reported.

Sturgeon will to write to May later this week, formally requesting the UK government temporary powers to hold a fresh independence vote around spring 2019, when Britain is expected to leave the EU.

The UK had voted to leave the EU in a referendum on June 24, 2016, after which David Cameron, who had campaigned for the country to remain in the bloc, resigned as prime minister. The UK government had rejected a petition calling for a second referendum. May took charge on July 11 to implement the result of the vote along with her team.