DAVID Cameron will invoke the memory of the late Labour leader John Smith - who died 20 years ago this week - when he arrives in Scotland today for two days of campaigning.

The Prime Minister is intent on delivering a positive, feel-good message, urging Scots to stay with the UK amid accusations of negative campaigning during the referendum.

Senior Tories have privately urged him to meet more ordinary people; his latest visits to Scotland have seen him on a nuclear submarine, on an oil rig and in a boardroom.

"Why not meet people in Saunchiehall Street? Why not go to Shetland or Stornoway?" insisted one Conservative grandee, who feels the Prime Minister needs to present a more three-dimensional figure to get away from the SNP caricature.

Mr Cameron said last night he had been "heartened to see so many people finding their voice. People from all walks of life and all parts of the UK know, as I know, that we are all better together."

He went on: "Twenty years ago this week, the Labour leader John Smith died. Whatever people thought of his policies, nobody could argue that he was a proud Scot who wanted the best for his country.

"And why not? Like millions of other people, he knew that loving your country and at the same time wanting to be part of something bigger does not make you any less Scottish. That truth is shared by millions of others.

"So my message is simple. We want Scotland to stay. We are all enriched by being together."

As a poll this week illustrated that voters feel the referendum debate is steeped too much in negativity, particularly on the anti-independence side, Whitehall insiders have accepted that the UK Government's message has been tilted too much towards the negative. Mr Cameron's visit is meant to redress the balance, placing the emphasis more on how the Union has been, is and will be good for Scots.

He is expected to clear the decks and concentrate on saving the Union once the May 22 European elections are over.

Sources have suggested he intends to spend much more time north of the Border; Labour leader Ed Miliband is said to be planning to visit Scotland at least once a month before the September poll.But Nicola Sturgeon dismissed the PM's visit as "part of a wholesale Tory takeover of the No campaign, which will prove disastrous for them".

She noted how the Conservative leader, recently branded "toxic" to the No campaign by a senior Labour figure, still lacked the courage to debate with First Minister Alex Salmond about Scotland's future.