They're on the march - the leaders of Britain's three main parties are heading to Scotland together in a rare show of unity.<br/> <br />The Prime Minister will also miss his traditional parliamentary questions.<br/> <br />That's unusual and a sign perhaps of the growing concern over the referendum on Scottish independence.<br/> <br />(SOUNDBITE) (English): BRITAIN'S PRIME MINISTER, DAVID CAMERON, SAYING:<br/> <br />"I want to do everything I can to put the arguments in front of the people. In the end it is for the Scottish people to decide but I want everyone to know that the rest of the United Kingdom and I speak as Prime Minister want them to stay."<br/> <br />Latest polls suggest the result is too close to call.<br/> <br />And new measures, including tax breaks, are being offered by the government to sway the undecided to No.<br/> <br />But the leader of the Yes campaign says the moves are a sign of panic.<br/> <br />(SOUNDBITE) (English): ALEX SALMOND, SCOTLAND'S FIRST MINISTER AND LEADER OF THE YES CAMPAIGN, SAYING:
