Labour whips see the vote as "a confidence issue," meaning a Government defeat could trigger a general election.
This is clearly a whips' tactic to bully recalcitrant Labour rebels to fall back into line. Many of them are in marginal seats, which would surely be lost if an election were called now. The rebels have a very tricky calculation to make, for if they support the abolition of the 10p rate they know that their electorates will hold it against them for a very long time. Conservative and LibDem opponents will already be drafting their leaflets.
The parliamentary arithmetic is fairly stark. More than 40 Labour MPs have already signed Frank Field's motion. If all of those carry through their threat and all opposition MPs turn up, the Government would suffer a hugely damaging defeat. And only a month later, they will suffer another one on the 42 days detention issue.
On top of this, Labour's local election results will hardly cheer up their beleagured MPs. The next month could well break Gordon Brown and his government