Senior backbenchers fear that Cameron wants the Liberal Democrats to win the Oldham and Saddleworth by-election

By Paul Goodman

Their reasoning is as follows.  The Prime Minister's political priority is to keep the Coalition together.  It's hard to see the Party pulling out of the arrangement.  It's easier to imagine the Liberal Democrats doing so: one doesn't need to list the rows that have taken place over VAT, student finance, housing benefit, the immigration cap and so on to prove the point (though some of the Government's biggest disagreements, such as those over prisons policy or the EU, are concentrated within one of the Coalition parties, the Conservatives, rather than between them).  The Liberal Democrats are a democratic party - as the Conservative Party is not - and Nick Clegg ultimately has to heed his MPs and members.

The opinion polls are a point of pressure on both - and the bulk of the spending scaleback, plus the pain it will cause, has scarcely begun to be implemented.  As a guide to what will happen at the next election, the polls are useless.  As a snapshot of present opinion, they're probably accurate enough, and they show that the party's ratings have plummetted: some surveys find that over half its support has gone.  Such findings don't exactly boost Liberal Democrat morale.  However, it would get a fillip were the party, in the face of the polling, to win the Oldham East and Saddleworth East by-election - and the Coalition, in consequence, would be strengthened (just a little, for a while.)

After all, the Liberal Democrats lost the seat six months ago by only 103 votes.  Therefore, senior Conservative backbenchers argue, David Cameron has an incentive to see them win it.  If the Party had come a bad third last May, they themselves and most of their colleagues would probably be of the same mind: they'd be willing to write the seat off in order to buttress the Coalition.  However, the Party came not a bad third, but a good one.  It gained 11,773 votes.  Phil Woolas, for Labour, took only 14,186.  So the Tories came in less than 2,500 votes behind.  On paper, the seat's a three-way marginal.  Part of it was in the former constituency of Littleborough and Saddleworth, held by the Party for over ten years.

Now think on.  If the seat reflects the national poll trend during the by-election - and it's sensible not to write off this possibility, even likelihood - the Liberal Democrat vote will collapse, and both the Conservatives and, in particular, Labour will pick up the pieces.  The most likely outcome (although the circumstances in which the by-election's been called render the result unpredictable) is a Labour hold, but if the Party's got a good shot of coming second it should surely - these backbenchers told me yesterday - strive to come first.  However, they added, Downing Street won't want it to, before launching into the explanation that I've tried to set out above.  Sources within the Government confirmed this afternoon that while the Liberal Democrats are already busy in the seat (see this and this on Twitter), CCHQ hasn't yet stirred.

They're surely right.  Indeed, each main party's got reasons to hope the poll takes place without anyone much noticing: the Liberal Democrats, because they'll probably lose; the Party, for the reasons I've explained, and Labour, because of the back story of why the by-election's being held in the first place.  If the Liberal Democrats failing to win the poll meant the end of the Coalition, I'd be rooting for them to win - since I want the Government, for all its flaws, to survive and prosper.  But this isn't the case: the Coalition will survive the loss by its minor partner of one by-election.  William Hague confirmed earlier today that the Party will fight the by-election. It should do so to win.