Benedict Brogan on his Daily Telegraph blog raises the prospect of the Conservatives not contesting the Oldham East and Saddleworth by-election. I hope this is mere speculation (or, coming from the Telegraph, mischief-making), but the Lib Dem leadership should discourage any suggestion that the Conservatives should not contest the by-election. Otherwise, we start to move from the realms of coalition, which is a business agreement, to some form of electoral pact, which would compromise the Lib Dems' independence.
The Lib Dem strategy in the by-election will no doubt be to harness the votes of both coalition parties against Labour, but they should do this the hard way, by squeeze messages, bar charts etc. to minimise the vote for the Conservative candidate. You can be sure that the local Conservatives will want to contest the seat, and one hopes that the leadership won't dissuade them.