Nicola Sturgeon resignation: 11 pictures as Nicola Sturgeon resigns at press conference at Bute House

In a shock announcement, the SNP leader told a press conference on Wednesday that she believes it is the “time is now” to stand aside but denied she is reacting to “short-term pressures” after a series of political setbacks.

The longest serving – and first female – First Minister said from her residence at Bute House in Edinburgh that she will remain in office while the SNP select her successor.

Nicola Sturgeon said her standing down as First Minister would “free” the SNP to take a decision on how best to pursue independence “without worrying about the perceived implications for my leadership”.

Speaking in Edinburgh, Ms Sturgeon said: “I feel that duty first and foremost to our country to ensure that it has the energy of leadership that it needs not just today but through the years that remain of this parliamentary term.

“And right now, in a very particular sense, I feel that duty to my part too. We are at a critical moment. The blocking of our referendum as the accepted constitutional route to independence is a democratic outrage.

“My preference of using the next Westminster election as a de facto referendum is well known.”

But she added: “I have always been clear that decision must be taken by the SNP collectively, not by me alone, but I know my party well enough to understand that my view as leader would carry enormous, probably decisive, weight, when our conference meets next month.

“And I cannot in good conscience ask the party to choose an option based on my judgment whilst not being convinced that I would be there as leader to see it through.

“By making my decision clear now I free the SNP to choose the path it believes to be the right one without worrying about the perceived implications for my leadership.”