Some writers and broadcasters have dared to use the 50th anniversary of the death of Winston Churchill to have a pop at the great man and I've been trying to think of a suitable punishment for them.

Perhaps they could be forced to live on war-time rations, or half war-time rations, or quarter war-time rations. Or perhaps they could be dropped in a field and forced, Cary Grant style, to flee a strafing by a Spitfire. It might teach them a lesson.

For the most part, the critics of Churchill have been re-heating all the old accusations of imperialism and egotism, but have missed, or refused to acknowledge, the moment in the leader's life and career that puts such accusations into their proper perspective. Jeremy Paxman summed it up in his new documentary Churchill: A Nation's Farewell (BBC1, Wednesday, 9pm) and used one of those short, nipped-and-tucked sentences that Newsnight taught him: Churchill stood firm, he said, when others might have buckled and were on the point of doing so.

Paxman didn't go into all the details of what happened, but the Churchillian moment in history is very familiar to any student of the Second World War. It happened on 28 May, 1940 when the War Cabinet met to consider a German offer of mediation that many of Churchill's colleagues were urging us to accept. What Churchill did instead was convene a meeting of the full cabinet and appealed to them directly: if we accepted the German offer, he said, we would become a slave state. Better to fight.

There have always been some who have tried to deny the significance of that moment and preferred to nip and snipe at Churchill - something that's nothing new. Indeed, Churchill had many detractors and critics, before and after the war, and in the most shocking moment of his documentary, Paxman revealed that even one of the most famous tributes to Churchill at his funeral 50 years ago was tinged with criticism.

Everyone knows what happened: as Churchill's coffin was taken up the Thames, the dockside cranes dipped their jibs in salute; the documentary showed the footage again and it is still extraordinarily moving and hard to get through without crying, particularly when we know how much the docks suffered during the Blitz.

But what is not so well known is that some dock workers initially refused to take part in the crane tribute because they didn't view Churchill as a representative of the working man; many only agreed to do so when they were paid. By the end of the arguments and divisions over the issue, the tribute went ahead but many in the docks took the reasonable view that if you respected the man, you would have done it for nothing, if you didn't respect him you shouldn't have done it at all.

What that little-known episode demonstrates is that the anti-Churchill cabal is not new and he has always been criticised by those who felt he didn't sufficiently represent their interests. But the footage of his funeral shown in Paxman's documentary revealed the bigger story: the pictures of the 300,000 people who queued to pay their respects as Churchill was lying in state in St Paul's; the pictures of the people who lined the route of his funeral procession, 10 or 12 deep, many with anguish on their faces. The footage of Churchill being cheered by crowds while he was PM is also impossible to deny. When was there ever a cheering crowd for Ed Miliband or David Cameron?

Paxman's point is that Miliband, Cameron et al are miniatures next to Churchill, but he also was issuing a warning that seemed all the more appropriate in the week we marked the 70th anniversary of the liberation of Auschwitz. In the 50 years since Churchill's death, said Paxman, there has been no sign of any politician like him and the implication of the observation was clear: luckily, in the years since the war, we have had no need of another a man made great by an hour of crisis, but one day the hour might come again.