Conservatives like George Young and Frank Field as leading candidates. It is likely Michael Lord, a deputy Speaker, may run. Sir Alan Haslehurst, also a Deputy Speaker, is another possibility. These too could attract some Conservative support.
What matters more is how Labour MPs will vote, given the much larger number of Labour MPs. There does not yet seem to be a Labour establishment candidate. Labour MPs do not necessarily warm to Frank Field, given the independent and critical role he has performed in recent years. A couple I spoke too favour John Bercow.
Alan Beith has also said he would like to stand. I have not yet come across any of his supporters.