A HARD Brexit without the protection of the single market and the customs union poses an economic threat to Britain which is "unparalleled in recent times", the SNP Westminster leader has warned.

Ian Blackford called on Labour to get behind the stance of the SNP and others in arguing Britain should stay in the single market and the customs union.

The MP for Ross, Skye and Lochaber said: "The first thing we're going to do is have the transition deal, the EU is making it clear through that transition deal we will remain in the single market and the customs union, that will create the pathway for us doing that over the longer term and I believe is consistent with the vote that took place in the UK last year."

Speaking on a Sunday political show, he said: "What we want Labour to do is to get behind us and others that are arguing that we should stay in the single market and the customs union.

"If you look at the agreement that has come forward over the last few days about full alignment in order to deal with the Irish question, the simple answer to that is to stay within the single market and the customs union."

He added: "I think the fundamental point is that nobody voted in that referendum to become poorer and it's about that threat which is becoming clearer to jobs and prosperity."

Blackford warned: "If we go into a hard Brexit without the protection of the single market and the customs union, there is an economic threat to this country which is unparalleled in recent times."

He called for the Prime Minister to pull the First Minister of Scotland and First Minister of Wales into the Brexit negotiations.