Gordon Brown and David Cameron will go head-to-head next month with high-profile attempts to woo business leaders.
The Chancellor and the Tory leader - expected to lead their parties into the next general election - will both address the CBI's annual conference.
The confrontation will follow a recent poll that shows Mr Cameron racing ahead of Mr Brown in the personal-popularity stakes.
Almost half of voters backed him as the next PM in the YouGov survey for the Daily Telegraph, compared with less than a third in favour of the Chancellor.
Mr Brown, who is a veteran of such occasions, said: "The CBI annual conference provides a welcome opportunity for me to speak to the business community about the economy and for business to speak to government about how we can make Britain more competitive."
His speech will come on day two - 24 hours after Mr Cameron's debut.
The Tory leader said: "I look forward to the chance to hear from the country's business leaders how politicians can best reach one simple but vitally important objective: to make Britain the best place in the world to do business."
Irish PM Bertie Ahern will also be among the speakers, as will many leading business figures.
CBI director-general Richard Lambert hailed the "formidable" line-up.
"With the help of some leading international business figures we will be tackling the biggest issues of the day: how can we meet the challenges and opportunities of China and India, secure our future energy supplies and ... and should UK business be up for sale?"
