John Longworth, director general of the British Chambers of Commerce (BCC), warns that "tawdry political tactics" could deflect from important issues facing the UK economy.
Such a focus, he wrote in a letter to Westminster leaders, had "been sorely lacking in political discourse".
The BCC represents thousands of firms.
"For many businesses, both small and large, one of the greatest sources of challenge and uncertainty in 2015 isn't the state of global markets, but home-grown politics," Mr Longworth cautioned.
He further decried politicians who "race between television studios and events to undercut their rivals' policy pronouncements, to proclaim themselves most 'in touch' with the needs of the people".
"You must focus on the causes, not the symptoms, of the challenges that face our United Kingdom," he said.
The UK's public spending, and wider economic matters affecting the country, will be among the most hotly contested issues in the run-up to the next general-election, scheduled for May 2015.
In his letter - addressed to PM David Cameron, deputy PM and Lib Dem leader Nick Clegg, and Labour leader Ed Miliband, as well as other party leaders - Mr Longworth outlined some of the policies on the BCC's wish list.
He said the organisation wanted those in power to support UK companies that are "brave enough to sell products and services across the world," as well as help with training opportunities and new jobs for both the young and old.
The BCC also called for greater devolution across the UK, with more decisions made locally, and an end to what it termed "crushing input taxes".
"Maintaining corporation tax at 20% would be a sound beginning," Mr Longworth added.
The head of a major UK business group has called on politicians to rise above "point-scoring" in their general election campaigns next year.