Just what kind of foxy stuff the Secretary of State for Wales is currently up to will tax his ministerial colleagues' minds until he declares his intentions in London today.
Mr Redwood has, since boyhood, been a lover of Shakespeare and of the history plays in particular, with their interplay of personal ambition and national destiny. So while he may not agree with yesterday's question from the Liberal Democrat MP, Alex Carlile, on whether he is Brutus or Cassius, he will at least appreciate the reference.
The fact is that Mr Redwood is not a natural stalking horse for anyone. One of the factors that must be weighing on his mind against challenging Mr Major is, as a possible consequence, the election of Michael Heseltine who is not, to put it mildly, anatural ideological ally.
It is too simplistic to assume that he is trying to pave the way for a Michael Portillo leadership. Indeed, his decision to keep his counsel this weekend may have as much to do with challenging the assumption that Mr Portillo, and not himself, is the natural leader of the right. With the sole exception of Lord Mackay, John Redwood is almost certainly the most intellectually able man in the Cabinet.
Finally, Mr Redwood has consistently been loyal, in private as well as public, to John Major, believing hitherto that he provided the best bulwark against the pro-European assumptions of the other main rivals, Michael Heseltine and Kenneth Clarke.
To his own irritation, nearly every profile describes as him as being of "lower middle class" origins. In fact, his parents were classic self- improvers. His father rose from accounts clerk at a road haulage firm to company secretary. His mother was a shop manageress. And in a bookish, television-free, household, the young Redwood soared through Kent College, Canterbury, and Oxford.
And, impatient to get into the outside world, he completed his doctoral thesis on the relationship between science and religion on the London Underground while commuting to his first City job at Robert Fleming.
The main criticism of Mr Redwood, who went on to become one of Baroness Thatcher's most creative policy unit heads, is that he is unclubbable and impatient with most of those less clever than himself - and that means most Tory MPs.
But there are two important caveats to this: firstly, his inspired choice of the brutally down to earth David Evans as Parliamentary Private Secretary who did much to humanise him; and, secondly, that he has a feel for the populist Tory domestic agenda which eludes some of his fellow Euro-sceptics.
In favour of repatriating powers from the EU, while adamantly opposed to a single currency and distinctly wary of a referendum on the issue, he has no theological arguments about Europe to cloud his sense that the Government's immediate priority is to re-assure a core Tory support more concerned about personal prosperity.
Most famously he has been a scourge of wasteful bureaucracy, consistently arguing that deep cuts in public spending are possible by reducing overheads without cutting programmes.
His own copybook domestic life - his wife left her high-powered job as British Airways company secretary to look after their children - chimes well with the aspirations of many natural Tory voters.
Nor he is a knee-jerk Thatcherite. He had grave doubts about the poll tax and is a supporter of local government. He was also one of those who urged Mr Clarke not to raise VAT on fuel. It is also a safe bet that he accepts a centre right agenda to provide help for homeowners, some relief to thrifty pensioners, a reversal of reductions in the married couple's allowance, more tax relief for small businesses and an end to capping of local authorities.
What is clear is that he was irritated not to be told personally by Mr Major on Thursday, but by Michael Howard, the Home Secretary, of a tactic about which he had the gravest reservations and which was now presented to him as a fait accompli.
Mr Redwood clearly thought that Mr Major had a better chance of seeing off his rivals - and particularly Michael Heseltine - by waiting until a possible challenge in November. Whether that will now prove the catalyst for a hugely damaging defection today remains to be seen.
Mr Redwood faces an agonising dilemma. At one end of the spectrum he could possibly still - just - save his job in a Major Cabinet by declaring wholeheartedly for him today. At the other, he could believe he just has the slenderest chance of emulating Margaret Thatcher in 1975 and defeating the incumbent in one bold stroke.
A growing number of MPs on the right last night doubted whether he could retreat from such a course without damaging his own credibility.Reuse content