JOANNA Cherry has called on the SNP to rethink their strategy if Boris Johnson refuses to devolve the power necessary for a legally watertight second independence referendum.

Writing in The National today, the Edinburgh Central MP says the Internal Market Bill poses “potential problems for the strategy of staking all on the grant of a Section 30 order from this UK Government”.

Earlier this week, Northern Ireland Secretary Brandon Lewis shocked the Commons when he admitted that the new legislation would “break international law in a very specific and limited way”.

Cherry says the admission of illegality raises a number of questions.

She writes: “How should we deal with a Government that doesn’t obey international law?

"A Government that tries to oust the jurisdiction of the courts?

"A Government that is prepared to disregard the overwhelming mandate won for the current devolved settlement in the 1997 referendum?

READ MORE: Joanna Cherry: UK is a rogue state, Scotland needs a more innovative strategy

“Just how does one negotiate with a rogue state? Is it reasonable to continue with a strategy designed for dealing with a state that obeys the rule of law and respects democratic mandates or is something a little more innovative required? The Scottish Government has not ruled out recourse to litigation either in respect of the provisions of this bill or, indeed, in respect of the future refusal of a Section 30 order.

“But what will we do if court action fails or if we win but this rogue Government refuses to respect the judgment of the court?

“For the time being at least, it has been made very clear to me that these are decisions above my pay grade, but they are decisions which will require to be taken nonetheless.”

Nicola Sturgeon has said a second independence referendum will be in the SNP manifesto.