Gordon Brown to aides on eve of election defeat: I really am sorry

Gordon Brown speaks to Gillian Duffy on the campaign trail in April. He was later recorded referring to her as a 'bigoted woman'. Photograph: Suzanne Plunkett/Reuters

Now we know just how wretched Gordon Brown felt during the general election campaign.

These were the words of the then-prime minister to his closest aides after the last televised debate:

I really am sorry.

This insight into Brown's private thoughts has been provided by Hannah Rothschild, who was given special access to the Labour inner circle for a film about Lord Mandelson.

This is Rothschild's description of Brown's mood on the night of Thursday 29 April (Rothschild's diaries wrongly record this as March 30; perhaps she wrote up events in the early hours of Friday 30 April as 30 March) after the final leaders' television debate in Birmingham. This took place a day after Brown had called the Rochdale pensioner Gillian Duffy a "bigoted woman".

In her diaries, serialised in yesterday's Mail on Sunday, Rothschild writes:

Gordon is slumped on a sofa looking exhausted. Sarah is still ethereal. Gordon thanks his team profusely for their help and again apologises for letting them down. It is genuine and heartfelt.

Suddenly I see why the faithful like him. "I really am sorry," he says again. There's an air of force jollity but everyone knows it's over.

This is one of the most powerful moments in Rothschild's diaries. The rest of the diaries tell us what we know already. The film is Mandelson's last great vanity project, proving once again that the great political sage always makes a terrible mistake when he has to make decisions about himself.