Meanwhile.
"The prime minister has defended the decision not to publish an independence referendum poll that was commissioned by the UK government.
David Cameron told BBC Scotland the government did not routinely publish its opinion research.
But he said the findings of the government's polls were largely in line with other recently published polls."
And another contrary voice.
"David Cameron received a blow on the first day of a visit to Scotland when a former senior British diplomat said "tough but sensible" negotiations would be held on forming a currency union in the event of a vote for independence.
In a challenge to the prime minister, who will reiterate his rejection of a currency union during his two-day trip to Scotland, the former British permanent representative to the Organisation for Security and Co-operation in Europe accused the government of arrogant behaviour towards the people of Scotland."
Better Together clearly have a job of work to do if they want a decisive pro union result in this campaign.