A GRASSROOTS drive for independence will be launched in Glasgow today, as 800 activists gather to discuss the policies, strategy and campaign to secure a Yes vote next time.

Chaired by the actor Elaine C Smith, the sold-out Scottish Independence Convention is billed as “a conference to prepare for the next independence referendum”.

Despite Nicola Sturgeon offering to park a second referendum to secure a soft Brexit deal for Scotland, the first speaker will be the SNP Communities Secretary Angela Constance.

Also speaking are SNP MP Tommy Sheppard and former SNP enterprise minister Jim Mather, a member of the SNP commission reviewing the economics of independence.

Scottish Green co-conveners Patrick Harvie MSP and Maggie Chapman will also address the event alongside Radical Independence founder Jonathon Shafi, and Robin McAlpine, creator of the Common Weal think tank which aims to influence SNP policy.

The gathering reflects impatience in parts of the Yes movement that the SNP has not yet updated its case for independence since the 2013 White Paper which failed to convince voters on the economic or currency implications of leaving the UK.

Mr Harvie, who this week predicted a referendum as early as spring 2018 if Theresa May rejects a bespoke Scottish Brexit deal, admitted the Yes side had lost the support of some of the 45 per cent who backed it before, and it was time to start actively campaigning again.

He said: “Independence supporters must build a strong case if we’re to convince everyone who voted Yes to do so again, as well as the many No voters who don’t want Scotland to be dragged along with the UK’s self-destructive Brexit process.”

Ms Chapman added: “As the creaking British state lurches from crisis to crisis, the need for independence becomes clearer and clearer."

Ms Smith said: “The indy movement needs to get chatting again. There’s lots to be done and 2017 is going to be a very important year. So it should begin with a proper get together of everyone in the independence movement to start to plan a way forward.”

The First Minister has ruled out a referendum in 2017, but left the option open beyond that.