Conservative leader candidate Mr Michael Portillo said today he expected eurosceptic candidate Mr Iain Duncan Smith to be ahead of him in a first round vote.
That would mean Mr Portillo, would battle Mr Kenneth Clarke for a second place in the final, two-horse race.
"My assessment now is that Iain Duncan Smith will certainly qualify and it's between Ken Clarke and me", Mr Portillo told BBC Radio. Mr Portillo and Mr Clarke resume battle on Tuesday when Tory MPs vote to eliminate one of them before 300,000 rank-and-file members across the country choose between the final two.
The battle could have profound implications for Britain's currency debate - whether to join the euro or not.
While Mr Portillo and Mr Duncan Smith both oppose ditching the pound, Mr Clarke is equally convinced Britain should join the European single currency club.
Mr David Davis withdrew from the campaign yesterday after coming fourth with 18 votes and promptly threw his weight behind Mr Duncan Smith.
Grassroots Tories are desperate for a more daring, charismatic leader to succeed Mr William Hague who announced his resignation after the party lost its second consecutive general election in June.
The euro is one of the most contentious issues within the Conservatives and could still be the nail in Mr Clarke's political coffin.
Mr Portillo emerged as the frontrunner after Thursday's first ballot but not by the margin many had expected, capturing 50 votes versus Mr Duncan Smith's 42 and Mr Clarke's 39.
But with 35 votes up for grabs from those MPs who voted for Mr Davis and ex-party chairman Mr Michael Ancram, who was eliminated in the first round, the race is too close to call and campaign teams will spend the weekend furiously canvassing.