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".
Chancellor George Osborne has hailed an "unprecedented" intervention from business leaders praising the Tories' economic plans.
"An intervention on this scale and with this clarity from Britain's business leaders is unprecedented in any recent general election," Mr Osborne said.
"Over 100 business leaders, heading up some of our largest companies and most famous brands, and employing over half a million people, have spoken out.
"And the warning from Britain's business leaders couldn't be clearer: a change of course will threaten jobs, deter investment, send a negative signal about our country and put the recovery at risk."
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.