A letter from the Scottish Government formally requesting power to hold a second independence referendum has been delivered to Theresa May.
Scotland's first minister Nicola Sturgeon has been pushing for a second referendum since the UK voted to leave the EU last June.
"It is my firm view that the mandate of the Scottish parliament must be respected and progressed," Sturgeon wrote in her letter to the Prime Minister, according to the Press Association.
Earlier today, the Scottish government tweeted a video of Sturgeon explaining why she has asked for formal powers to hold the vote on independence.
Sturgeon announced her intention to hold a second referendum earlier this month. At the time, the Scottish National Party leader said the "material change of circumstances" brought about by the Brexit vote justified the repeat of the 2014 referendum, adding "if the Scottish parliament gives me that authority then that should be respected by the UK government".
"The Scottish government's mandate for offering this choice is beyond doubt," she said.
The PM has previously said that "now is not the time" for a second vote, despite Sturgeon's call for a ballot to take place between Autumn 2018 and Spring 2019.
May said it would be wrong for any vote to take place before Scots can see Brexit in operation.
"When the SNP government say that now is the time to start talking about a second independence referendum, I say that just at this point all of our energies should be focused on our negotiations with the European Union about our future relationship," she added.
"To be talking about an independence referendum would, I think, make it more difficult for us to be able to get the right deal for Scotland and the right deal for the UK."