He is widely known to have delivered the most intellectually interesting speech of the contest.
Ken Clarke talked about him having been in the back room for far too long and his lieutenants praised him.
David Cameron actively sought his support but David Willetts is now expected to back David Davis imminently.
David Willetts' endorsement of the Shadow Home Secretary will be a critical development in the race and will give Mr Davis' promise to build a Conservative Party of all the talents much added credibility.
Many of the party's more moderate and socially inclusive members will see David Willetts' endorsement as a 'permission slip' to embrace the Davis candidacy.
This is by far the biggest boost to David Davis' campaign to date and I personally hope that Mr Davis will fully embrace David Willetts' message of social reform.