But with three dozen of the 164 Conservative MPs remaining uncommitted, the race was still wide open and frantic last-minute efforts were being made to woo and seduce the hard-to-get waverers.
For an outright win a candidate requires at least 83 votes - a majority of Tory MPs - and a majority of at least 25 votes over the runner-up, a lead of 15 per cent of MPs.
No one is expected to get over those hurdles, in which case a second ballot will be held next Tuesday in a race that will be open to new contenders - and the possible withdrawal of any candidate who does particularly badly when first-round results are declared before 6pm tonight. The uncertainties are aggravated by the possibility that Mr Clarke could top today's poll - and still not have enough steam to get him the required 83-vote minimum to win the second ballot.
He needs more than 50 votes today to remain a credible contender for next week.
The right-wing were jostling for a contender who could pick up the Thatcherite banner - with Michael Howard, Peter Lilley and John Redwood all in contention. Whoever gets most votes from the right could still give Mr Clarke - or Mr Hague - a close run in the final ballot on 19 June.
But last week's confident assertion of Mr Howard's supporters that he was running second to Mr Clarke was badly dented by the fact that as many as half a dozen claimed votes have since defected. They included Alan Clark who is undeclared, and Eleanor Laing and David Tredinnick who have declared for Mr Hague. Claimed declarations from the different camps put Mr Clarke and Mr Hague on 33, Mr Howard on 25, Mr Lilley on 22 and Mr Redwood on 17. That left 35 undeclared.
Mr Clarke would win if the ordinary voters had a say: an ICM poll in today's Guardian gives him 31 per cent, well ahead of second-placed Mr Redwood and Mr Hague, each on 9 per cent, with Mr Howard on 7 per cent and Peter Lilley on 6 per cent.
Today's voting, which starts at 10am in a Commons Committee room, will be preceded by the results of an advisory ballot of constituency party chairmen and senior activists. Any gross disparity between that and today's ballot could add to pressure for party members to get a vote - as could reports that a party chairman in Essex was refusing to pass on his constituency ballot because it supported Mr Clarke, which he did not.Reuse content