Of course it’s about the leadership (which is why we can’t say it’s about the leadership)

There are times when the truth has to be officially denied by those on opposite sides of the argument. Today’s tax debate is one such occasion.

The ‘50p question’ has become a totemic one for the Lib Dems.

The Tax Commission is proposing the party abandon its commitment to income tax increases for the richest in favour of income tax cuts for the poorest - to be funded by raising taxes on pollution and wealth. “Tax pollution, not people” is the slogan - and it’s a good ‘un.

The so-called ‘rebel amendments’ that is being debated 50 yards from me seeks to tack-on a symbolic hike in income tax for the rich - a marginal rate of 50% for those earning more than £150k. Its proponents argue that this is complementary to the Tax Commission proposals, that the party can have its cake and eat it. “Tax pollution, and people” seems to be their slogan. I’m unconvinced.

The party leadership has thrown its weight behind the plans. But, this being the Liberal Democrat party, they cannot say it’s about the leadership. “It’s not High Noon,” declares Ming Campbell.

Politically this is the only smart option. Because Lib Dem members are an ornery bunch of contrarian individuals, and anything that smacks of an establishment attempt to corral or whip us into line will be rejected on principle. To state the bleedin’ obvious: this is both the party's strength and its weakness.

Those rebels leading the charge to retain the 50p commitment are equally careful to avoid confrontation. “I am strongly supportive of [Ming’s] leadership but he recognises … that the party conference makes policy,” says ‘rebel’ MP Evan Harris.

Again, this is sensible. Because if there’s one thing the Lib Dems dislike more than the leadership seeking to struts its stuff, it’s attacks on the leadership (in whatever guise) which give succour only to our opponents.

So both sides are doing the Right Thing. It’s just that the Right Thing sometimes exists only in a parallel universe.

I am in no doubt, and nor is anyone else I’ve spoken to today, that a defeat for the Tax Commission proposals will be a damaging defeat for the leadership, and personally undermining of Ming’s authority.

But that’s not why I’ll be voting with the leadership. The Lib Dems have the chance today to show we’re not fighting yesterday’s battles. There’s no need: we’ve won them already. Everyone now agrees that well-funded and locally-accountable public services are vital.

Let’s now devote our energies to winning tomorrow’s arguments: that we need new ‘green taxes’ to tackle climate change, taxes on the wealth of the very richest - so that we can cut the taxes of the poorest, and make real our commitment to social justice.