Listening to the former Home Secretary Charles Clarke follow up on radio this week his New Statesman attack on Gordon Brown, I tried to put myself into the mindset of Mr Clarke's colleagues: a parliamentary crew facing shipwreck at the next general election. I consulted my own experience inside and outside politics. And immediately the picture clarified. Here's what I saw.

First, for the great majority of the Parliamentary Labour Party with no job in government, you can largely discount the issue of Labour losing power. So long as they retain their seats they keep the job they have - that of a backbencher.

I recalled fighting my first election as a Conservative candidate in West Derbyshire in 1979: “How are we doing?” I asked my election agent.

“Well, it could be tight..,” he said. My heart sank. West Derbyshire was supposed to be a safe Tory seat. Was I proving such a disaster as a candidate? “...one commentator thinks it might even be a hung Parliament.”

I relaxed. It was the national picture my agent was talking about. Hang Mrs T's prospects so long as mine - of being an MP - were secure. You may be sure that the most pressing thing on the minds of most Labour MPs this weekend is their own majority at the next election, not their party's.

Then I cast my mind back to the next time in my life that unemployment had seemed to loom. I had left politics and become presenter of LWT's Weekend World. Within a year it was becoming clear that I was failing. Whispers about the demise of my programme began. Some way into my second year we heard that LWT planned to axe us in about eight months' time.

Did my thoughts move to the careers that I might seek thereafter? Did I lie awake wondering where my true strengths lay and how to tap them? Did I seriously consider how to alter my fate? No. That cut-off point, that final show in the summer of 1988, became an almost opaque barrier past which I could not look: a sort of death, a void. If only my programme could be reprieved for two more years. Or a year. Or six months. Or even a couple of shows after the summer, to cover the party conferences. In everything I heard, I listened for indications of a possibility that I might get a few months more, rather than a few months less, in the job.

This was irrational. Indeed, I should have been thinking about resigning early - on a point of principle - before I was pushed. But Dr Johnson is wrong. The prospect of being hanged in two weeks does not concentrate the mind. It numbs. Paralysed like a rabbit before a snake by that ticking “time still to go” clock in the corner of the screen, your brain is drained of deeper thoughts.

And so it will be this morning for hundreds of Labour MPs. Few will have much confidence that, after the spring of 2010, there will be any kind of employment that would pay better than the £90,000 or so to which a backbencher's salary effectively amounts, including expenses. 2010 is the wall, the void.

It is to these anxieties that Gordon Brown's lieutenants are this weekend whispering. “It's still only 2008. With Gordon, you're totally secure until 2010. Who knows what may turn up in the interim? Why throw everything now into a gamble, when the only certainty would be that a new leader would feel obliged to call an earlier general election where your own seat might be lost?”

As Peter Riddell pointed out in The Times yesterday, some may hope - but none could be confident - that a new leader could pull back a couple of lost percentage points in the polls; and even then the seats saved would be a small number.

So the argument that follows is probably naive, the likelihood being that Mr Brown will plough on to the bitter end.

But against all that I say this: Labour's predicament had now gone beyond an internal party matter, beyond a calculation of numbers and probabilities. It is a national predicament. It is an emergency - a challenge to which a decent party should be able to rise. In the immediate term Britain is heading into a recession with a doomed and flailing leadership at the helm. In the longer term the pride and confidence of a whole political and philosophical movement, the British centre left, is on trial. And in very personal terms, the courage - I would almost say the honour - of a small number of men and women, Mr Brown's Cabinet, is being tested.

David Miliband, Alistair Darling, Jack Straw, John Hutton and Alan Johnson know that it lies within their power to wrench the tiller from this man's hands.

Alan Johnson knows that he could be prime minister by Christmas if that happened. None of them can know if this would rescue Labour's immediate electoral prospects: probably the next election is lost. But they surely sense that to stir themselves in a crisis and - win or lose - to have admitted and confronted an unfolding political disaster would be to show the honesty and moral confidence that will be so important on the other side of that blank wall: the coming general election.

The Parliamentary Labour Party, the party nationwide and the trade union movement, should be asking themselves how the 20 months ahead are going to look to an emerging generation and to history.

How would paralysis reflect on a political movement with claims to a future in the new century? How proud they are going to feel about the way they handled the recognition that, at a dangerous time at home and abroad, their party had landed itself with the most inept and directionless Prime Minister in British history; and with nearly two years left to go. This is about more than electoral arithmetic. It's about showing that a party has a heart, a mind and stomach for a fight; that it can stir itself in an emergency.

And yet even outside the formal confines of the Labour movement - in the universities, in the newspapers, in the broadcast media - where are the voices raised from the Left, prepared to acknowledge this spasm, and distinguish between the failure of an individual, and the failure of an ideology? Is Polly Toynbee almost on her own? Has the whole centre left project lost its self-belief, taking refuge only in days, hours and minutes left profitlessly in office?

The present Cabinet should pierce the mental wall presented by the next election, whenever it comes, and think about official opposition. It should think about a leader then who can hold his head up and say that he didn't hold back, waiting for someone else to show some guts. In the balance for Labour this autumn is not so much Labour's next general election, as its self-respect. The first is lost already. The second is in peril.

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