More than 100 business leaders have declared their support for the Conservatives, warning a "change of course" after the general election would "put the recovery at risk".
Senior executives from leading British companies - including five who have previously backed Labour - signed an open letter praising the Conservative's economic policies.
Labour dismissed the letter as "nothing new".
Shadow Chancellor Ed Balls has been criticised by the Tories for his comments on ITV News West Country last night, in which he 'refused' to rule out lowering the 40p tax rate threshold if Labour win the election.
George Osborne today accused his counterpart of proposing to tax middle earners and said: "He has made it pretty clear I think that he wants to drag more people into that 40p rate of tax... I think that is wrong now and the Conservative party has a very clear plan to raise the threshold to £50,000."
Labour said the claims that Balls was effectively leaving the door open to changing the threshold was "Tory nonsense", and stated: "Ed Balls was clear and Labour's position is clear: we want fewer people paying the 40p tax rate. We want to ease burden on working families."
More than 100 people claiming to represent working people across Britain have signed a letter backing Labour in the general election.
Tories take campaign to the factories of three businesses who publicly endorsed their economic plans.
Read the letter carefully, don't worry, it's short. Note that while it praises the Conservative-led government it does not mention Labour.