Shadow work and pensions secretary says Conservative MPs apologised to her over Duncan Smith's claim that she had not bothered to vote.
Both of the main parties see political advantage in going it alone if they win in 2015.
The party is determined not to allow the Conservatives to make Labour failure the story of Thursday's by-election.
The Chancellor is still confronted by the awkward truth that for most people there is no recovery at all.
Trailing to Ukip on immigration and to Labour on the NHS, the Conservatives' best hope may be an economic slowdown that persuades voters the storm has not passed.
Both parties will be portrayed as unserious and lacking in credibility.
Our hard-fought victory in Heywood & Middleton stands in stark contrast to the Tories' collapse in Clacton.
They need to focus on winning tactical votes from Labour supporters to hold on to their MPs.
The Conservatives' brand weakness means they may struggle to reach the level needed to be the largest party.
The party risks leaving itself open to a "tax bombshell" attack by Labour.