Theresa May has refused to apologise amid claims her attitude to Brexit is risking the break-up of the UK.
The prime minister came under attack yesterday from Labour MP Ian Murray who called her government as big a threat to the Union as the SNP.
Over the weekend, she appeared to indicate the UK would leave the single market to control immigration after Brexit.
During prime minister’s question time, the former shadow Scottish secretary, who is Labour’s only MP north of the border, said: “Here is a message you may find disagreeable.
“Your lack of priority for the single market is putting jobs in Scotland and the economy at risk.
“That means your government is as big a threat to the Union as the SNP; your government is not worthy of the trust of Scots.
“Will you take this opportunity to apologise for threatening the Union and give a solemn promise to every single person in this country that they will not be a penny worse off after a Tory Brexit?”
Mrs May insisted she wanted to secure the best possible deal for the UK with the EU and “the best possible deal for trading with and operating within the single European market”.
She added: “Unlike the sort of downplaying that you do about the approach that we are taking, I have to say that it is this government that is ambitious for the opportunities that are available to this country once we leave the European Union.”