Now Tory grumblers must toe Dave's line

And perhaps surprisingly, it's the Tories who have taken the initiative.

Within a day of the poll being called, the Tory leadership swept aside various Ealing worthies to select as their candidate a man named Tony Lit, a charismatic millionaire businessman, extremely well known in the constituency, who runs the local Asian radio station. I'm not saying the Tories will win Southall it's a pretty big stretch. But if anyone can do it for them, it is probably Mr Lit.

The reaction of Tory members to the prospect of electoral success was exactly as you'd expect. They were against it. Who was this Lit? He hadn't even been a member of the party! "A controversial and high-risk choice," blogged an Ealing Tory councillor. Reminiscent of the ruthlessness of New Labour, sulked someone else.

Yes, New Labour were ruthless.

Perhaps that's why they kept winning.

And in New Labour, if some councillor publicly dissed his own candidate, three weeks before polling day in a crucial by-election, that councillor would instantly be vaporised, leaving only a Hush Puppy shoe-print to mark where he'd once been.

The Tory Party's chronic discipline problem is highly relevant to the politics of the next few months, which will arguably be more decisive for David Cameron than for Gordon Brown. The new Prime Minister is still on trial with the British people. They sort of like what they see, but they won't really make up their minds about him for some time yet.

For the Tories, however, the next few months will decide whether

Brave reporter's Project Dave can stay in contention.

Success will not come through premature flurries of policy announcements, or precipitate attacks on Brown. There's no point deciding how to oppose a new prime minister until you know what he's actually going to be like.

Success will come through discipline.

Even though it elected Cameron by a landslide, his party has never really been comfortable with him.

Until now, criticism has been stilled by Tory opinion poll leads.

Now those have vanished, there must be a real risk that the dissenting voices will be raised, and the not entirely united Cameron Tory Party will start to fall apart..

If that happens, the election is over, whenever Gordon Brown decides to call it.

There's fault on both sides. Tory activists are often ignored by the leadership. But what they should recognise is that Cameron is their best hope. The voters quite like him; they don't like the Tory Party.

Maybe the lasting harm done by the grammar-school row, an unforced error if ever there was one, will have shown the dangers of division. Maybe Cameron's recent nudges to the Right the promotion of the family, the demotion of Francis Maude will be enough to stem the grumbling.

But in the next few months, we'll learn the answer to this question: are the Tories serious about winning?