AN SNP MP has argued that even if the UK were to stay in the single market, an independence referendum must take place.

It came amid continued calls by the party's Westminster leader, Ian Blackford, for the UK to stay in the single market and customs union after Brexit.

At Prime Minister's Questions yesterday, Blackford told Theresa May that it was the only way to secure a Commons majority for a Brexit deal.

However, the SNP's Angus MacNeil said the First Minister would still need to use the party's mandate for an independence referendum in that circumstance.

He tweeted: "For clarity, even if this good advice was heeded, the material change to Scotland's status in EU will happen and @NicolaSturgeon's SNP would need to use the independence mandate."

The SNP's manifesto in 2016 made clear that indyref2 could be called "if there is a significant and material change in the circumstances that prevailed in 2014, such as Scotland being taken out of the EU against our will".

Winning the 2016 Scottish Parliament election, the party secured that mandate.

Blackford has put May under pressure over the ever-increasing risk of a catastrophic no-deal Brexit.

"People’s jobs will be put at risk [by Brexit]”, he said, adding that these were the words of May herself in 2016.

He said: “No Prime Minister should negotiate a deal that threatens jobs. The Prime Minister must accept responsibility, avoid an economic catastrophe.

“Does the Prime Minister not understand that staying in the single market and the customs union is the only deal that will get through this House?"

May argued that her Brexit proposals would protect jobs and livelihoods in the UK.