Rather than be burdened with the overheads of a permanent agency relationship, the party has opted for a more flexible arrangement with Charles Vallance, a founding partner of Vallance Carruthers Coleman Priest, and Michael Moszynski, the chief executive of the M&C Saatchi subsidiary Immediate Sales.
Both VCCP and Immediate Sales will provide creative resource when necessary.
However, the Tories have entered into a more formal agreement with the Havas-owned Media Planning Group, which will handle its media requirements.
The new system has been put in place by Will Harris, the former marketing chief of O2, who was appointed as the party's head of communications at the end of last year.
The arrangement resurrects the professional relationship between Harris and Vallance that began when VCCP was appointed to handle O2's £45 million account two years ago.
Maurice Saatchi, the Tories' joint chairman, recommended Moszynski, a former chief executive of M&C Saatchi in Hong Kong, to Harris.
The news emerged as the Tories launched a new poster campaign spoofing the Linda Barker ads for DFS.
They show Gordon Brown, dubbed "the credit card chancellor", sitting on a sofa with a picture of Tony Blair above him. The headline reads: "Labour's special offer. You won't pay until 2005."
Harris said: "It's important to talk to people in their own terms and make our message more relevant."