Clarke moves closer to the second round

Tory leadership » Ex-chancellor is moving quickly through the field and looks likely to be Michael Portillo's main challenger

Kenneth Clarke ­ the pro-European candidate for the Tory leadership ­ has enjoyed a significant spurt of support from Tory MPs since his declaration to run.

In just a few days the former Chancellor of the Exchequer has added six definite names to his list of backers and is now seriously challenging for one of the two slots in the ballot of members.

But his hopes, along with those of Iain Duncan Smith ­ the right-winger whose personal support also blossomed last week ­ depend on winning the support of the 75 Conservative MPs still to declare and, more crucially, the second preferences of candidates likely to be knocked out in the early rounds.

Michael Portillo already looks certain to win enough support from MPs for his name to be one of two to go forward to a vote of the whole party. Thirty-six MPs have declared for him and according to a poll carried out by The Independent on Sunday he has five further possible backers.

Mr Duncan Smith is in second place with 20 declared backers ­ an increase of seven in the course of a week. Mr Clarke now boasts 16 declared supporters with a further eight possibles.

Michael Ancram has 10 declared supporters and four possibles, though his campaign team insist his support is "somewhere in the 30s". David Davis, the arch-Eurosceptic and the bookies' "dark horse", is at the back on nine at the moment, with four possible additions. But his team have said: "We're sure that Ancram hasn't got in the 30s. We're confident we're ahead of Ancram."

In reality, the votes of Mr Ancram and Mr Davis ­ if they are, as expected, knocked out in the early rounds ­ will be critical in the race for second place. Westminster insiders believe the Eurosceptics around Mr Davis would naturally back Mr Duncan Smith as a second preference, while the old guard and moderates in the Ancram fold were more likely to opt for Mr Clarke. Both camps insist that is not necessarily the case but Tory sources seem certain "they won't go to Portillo".

Mr Duncan Smith's camp believes that, following Mr Clarke's remarks on the euro at his campaign launch, that his "battleground" will be winning support back from Mr Portillo, as even some of Mr Ancram's supporters could go over to them on the issue. This week, the contenders will start to take their platforms to the party members, the people who could elect them leader if they win enough support among MPs to make the ballot paper. The first ballot will be held on July 10 and the final result will be announced in September.