THERESA May must not make any attempt to block plans for a second referendum, Nicola Sturgeon has warned.

The First Minister has said she has a “cast iron mandate” to hold the poll and reminded the Prime Minister she is yet to win a Westminster election.

Ms Sturgeon responded to Ms May’s statement that the SNP should focus on governing for Scotland and suggestions she could put a condition of only allowing a vote after Brexit happens and if the SNP wins a majority in Holyrood.

Following a meeting of the Scottish Cabinet, the First Minister said: “It should be up to the Scottish Parliament to determine the referendum’s timing, franchise and the question.

“There should be no strings attached, no blocking mechanisms applied and no Downing Street diktat. Scotland’s referendum must be made in Scotland.”

She added the Scottish Government “has a cast-iron democratic mandate for an independence referendum”.

On twitter she contrasted her position with that of Theresa May.

She said: “Trading mandates does not put PM on strong ground.

“In addition, I was elected as FM on a clear manifesto commitment. The PM is not yet elected by anyone.”

Ms May spoke in the House of Commons as the Brexit Bill was passed giving her the power to start negotiations with the EU for the UK to leave.

She said: “This is not a moment to play politics or create uncertainty.

“It is a moment to bring our country together, to honour the will of the British people and to shape for them a better, brighter future and a better Britain.”