Nicola Sturgeon did not announce the date of a new referendum on independence at the SNP conference this weekend. However, she made clear that if Scotland is not able to secure the form of government that best suits the needs of its people, then an independence referendum will be unavoidable. Scotland requires membership of the European Single Market, powers over immigration and a legislative consent motion in Holyrood on the terms of Brexit.

Sturgeon is right to say that, while the EU referendum vote makes Brexit inevitable, it did not give Theresa May a mandate to bypass parliament and pull Scotland out of the European Single Market and free movement. The Foreign Secretary, Boris Johnson, repeatedly stated during the referendum campaign that Britain could remain in the single market after Brexit. The UK Conservative election manifesto said Yes to the single market.

MPs in Westminster must now, as the First Minister says, be given the right to vote on the terms of Brexit. It is a violation of our constitution for the Prime Minister to drive through the greatest legislative change in half a century under royal prerogative without an endorsement from parliament. The First Minister is right to seek a coalition with the other opposition parties in Westminster to fight against Brexit dictatorship.

It would also be “constitutional vandalism” as the First Minister put it, for the Scottish parliament to be refused a say on Brexit and the powers devolved to Holyrood after Britain leaves the European Union. The 2016 Scotland Act made the Sewel Convention, under which the Scottish Parliament must give consent to Acts of the UK parliament that impinge on its powers, a legal requirement. The repatriation of powers from Brussels will involve many matters which are under the remit of Holyrood, from the environment to agriculture and fisheries.

It is now up to the other parties in Holyrood, Labour and the Liberal Democrats, to follow the First Minister's lead and speak with a common voice against the arbitrary exercise of executive powers by Theresa May. The PM's refusal to recognise the right of legislative consent not only cuts across Holyrood's powers, it undermines the devolution settlement itself.

These are not abstract matters of constitutional theory. Brexit will affect the rights and welfare of every voter of Scotland as we lose the protections of the EU citizenship against our will. If Number 10 refuses to recognise legitimate Scottish demands, a repeat referendum will not only be an option - it will be a constitutional necessity.