Nicola Sturgeon will make an "important" speech on Monday ahead of the UK Government's expected triggering of Article 50.

The First Minister will speak at Bute House, her official residence, at around 11.30am.

There will be a livestream of the First Minister speech on the STV News Facebook page.

Theresa May could begin the formal process of leaving the EU as early as Tuesday, following a vote at Westminster.

During Monday's speech, it is thought Sturgeon could issue a final ultimatum to the UK Government to include keeping Scotland in the single market as part of their Brexit negotiations.

The First Minister could also call for a second independence referendum or demand a section 30 order which would grant the Scottish Parliament the power to hold the referendum.

Immediately following the Brexit vote last June, the First Minister said a second independence referendum was "highly likely."

The First Minister tweeted on Monday morning: "This morning, I'll make an important speech in Bute House ahead of the triggering of Article 50."

Triggering article 50 will begin a two-year negotiation period as the UK discusses the nature of its departure from the EU.

The Scottish Government has called for a special deal post-Brexit which would keep Scotland in the EU single market but UK ministers have not indicated they would allow this.

A number of Scotland's opposition party leaders have said they would be opposed to any second vote on independence.