DAVID Cameron will throw himself into the independence campaign with a two-day visit to Scotland this week as Whitehall prepares to put a precise figure on how much the United Kingdom benefits each and every Scot, the so-called "Union dividend".

While No 10 declined to go into detail about the Prime Minister's itinerary, his on-the-ground offensive will begin in Glasgow with a Commonwealth Games-themed visit and will include media interviews, covering not only the independence question but also the run-in to the European parliamentary elections on May 22.

On his recent visits to Scotland, Mr Cameron has been seen on a nuclear submarine, an oil rig and chairing the UK Cabinet in a boardroom.

He has come under fire for "jetting in and jetting out" on day trips.

Today, Ruth Davidson, the Scottish Conservative leader, will speak at a special political Cabinet, where she will brief Tory colleagues and update them on the referendum campaign.

It is understood Mr Cameron and his senior colleagues now fully accept the need for a far more positive slant to the pro-Union argument.

Later this month, following the Euro poll the PM will concentrate wholeheartedly on the fight to keep Scotland within the UK with two distinct campaign phases pencilled in for May/June and August/September.

In the last week of May, the Treasury is set to publish what it regards as a key document, which some believe could be a game-changer in the independence debate. Tomorrow, George Osborne, the Chancellor, and Sir Nicholas Macpherson, the Treasury's chief civil servant, are expected to make mention of the paper as they are cross-examined by MPs on the Commons Scottish Affairs Committee.

The department's top economic experts have spent weeks number-crunching the Scottish Government's White Paper and have not only "filled in the gaps" the costs opponents say are missing from the SNP administration's document - also come up with a per capita figure by which each Scot benefits from being part of the United Kingdom.

Previously, the Lib-Con Coalition has produced numbers, which have estimated how much Scots would lose if they chose independence.

In an attempt to put a more positive sheen on its argument, the UK Government will before the end of the month, in its most rigorous analysis to date, produce a figure by how much Scots gain individually from being citizens of the UK. It is expected to run into thousands of pounds per year.

Meanwhile, the head of a UK-wide association for boarding schools has said Scotland would be better off remaining part of the Union.

Ray McGovern, chairman of the Boarding Schools' Association, made the comments at the organisation's annual conference in Glasgow. He told delegates:"I am through and through a Scotsman, but I am also British and I believe Britain is a great country and Scotland should remain within it."