Here is the May 2010 result.
Labour 14186 (31.9%, -10.7%)
LibDem 14083 (31.6%, -0.5%))
Conservative 11773 (26.4%, +8.4%)
BNP 2546 (5.7%, +0.6%)
UKIP 1720 (3.9%, +1.8%)
Christian 212 (0.5%, +0.5%)
If the changes in the party standings in the current national opinion polls since May were directly projected onto the Oldham East and Saddleworth constituency, that would lead to a result along these broad lines:
This morning, ComRes for the Independent on Sunday and Sunday Mirror has Labour on 39% (+10 since the general election), an increase of over a third in the Labour share; the Tories are on 37% (+1), marginally up, while LibDems at 11% (-12) have lost just over half of their support.
Yet David Cameron stands accused of not trying to win the Oldham and Saddleworth by-election, and failing to take the usual steps to mobilise support for his party's candidate. The charge seems well founded. And the Prime Minister seemed to strengthen it in going out of his way to wish the LibDems well.
What is he up to?
The Prime Minister is probably right that the Conservative party is not likely to win the seat, whatever he does.
The true aim of this gently effective exercise in removing any momentum from his own party's campaign is to try to make sure the Tories finish third again. For the Tories could have a very decent chance of overtaking their Coalition partners unless there is an active effort from Downing Street to stir up Tory apathy in the constituency.
The projection from national polls is not a prediction. The election result will probably be very different from that. But it does capture why Conservatives have good grounds to say that they ought to have at least as strong a chance as the LibDems of taking the seat from Labour. There are equally good counter-arguments as to why the LibDems will hope to squeeze the Tories and take the seat. A 104 vote majority tells a story, which leaflets can exaggerate, as will the circumstances of the court case. Labour-LibDem local animosities having run deep for 15 years.
Yet the decisive factor that could well clinch this LibDem argument that it is primarily a Labour v LibDem contest will be Tory national leadership and media messaging accepting that is so, rather than attempting to challenge that in their own party interests.
Ladbrokes have Labour at ludicrously short odds - 1/5 on, with the LibDems (6/1) marginally ahead of the Conservatives (8/1) for the seat. (That is not quite the same as saying the LibDems are mild favourites to finish second; I am not aware of odds on that).
It would be foolish to make any firm prediction about who will win in Oldham in a very unusual election in a highly atypical constituency. One Labour MP with good knowledge of the region described the shortness of Labour's odds as bonkers. Many in the party expect a genuine scrap for the seat on the ground, whatever the national picture, given the many distinctive features of Oldham and Saddleworth.
But the political repercussions will not only be about who wins the seat - but the order of the three major parties on the podium on the night.
I expect the Tory right will probably make enough noise to secure assurances from Downing Street and CCHQ that they are fully behind their own candidate. How credible these assurances are may be open to question. That is largely because, if the Tory partisans were to get a fully committed campaign, they could do pretty well, putting up a decent fight for the seat, and have a very decent short at securing 2nd place at least.
The Tory Coalitionists in Downing Street fear that would come at too high a price.
I doubt they would turn down a Tory victory if they could have one. But they would like a LibDem victory perhaps just as much, were that possible.
The live fear is that a Tory second place could be a hammer blow to both the morale and unity of their Coalition partners for fear that it could destabilise the Coalition, making a bad set of LibDem results in May 2011 even more damaging. Those who want a campaign for a Tory majority at the next General Election might not be too worried about that.
So James Forsyth in the Mail on Sunday reports that a LibDem third place is considered a nightmare scenario by the Tory leadership as well as the LibDems.
The Lib Dems were in second place at the General Election, only 103 votes behind Labour ... If the Lib Dems win the seat, it would – in the words of one Clegg confidant– be a ‘game changer’. It would show that coalition is not destroying the party’s electoral prospects and would turn the spotlight on Ed Miliband, who has made the vote an early test of his leadership.
But the nightmare scenario for Clegg is that the Lib Dems are pushed into third place. This would suggest that the party is being destroyed by the Coalition.
It would cause a full-on panic in Lib Dem ranks. No 10 is acutely aware of this – the Tories are even soft-pedalling their campaign to try to stop it happening.
These fears of the consequences of a LibDem third may be somewhat overstated.
For one thing, they would only further dramatise a political reality which would remain the case if the party were a fairly distant second.
And, if the LibDems really are in the electoral doldrums, then they may have to cling closer to the Coalition until 2015, for fear of meeting the electorate any sooner. That could shift the balance of power in the Coalition further right.
On the other hand, if the LibDems appear to have no credible strategy for recovery, it might over time call Nick Clegg's leadership into question. But it is not clear what alternatives the party now has once it starts from here. They can hardly credibly say - before the next election - that they think they made a mistake in joining the Tory-led Coalition in May 2010, given that nobody (not even the very few silent refuseniks like Charles Kennedy) said so at the time.
But the humiliation for Nick Clegg of a LibDem 3rd place is the real reason why the Tories will avoid fighting whole-heartedly in Oldham, even for second place.