For me, Tony Blair’s departure from office is a bittersweet day. Just as it would have been wrong for him to leave office any sooner, so it is right that he is leaving office now, making way for Gordon Brown. Blair has a remarkable instinct for the mood of the public, and he knows that a decade is enough time for a prime minister to lead the nation. That instinct has never wavered: his grounding in his own constituency, and his empathy with hard-working, decent families, has enabled him to be one of Britain’s most successful PMs, and Labour’s most successful leader.

I think of the way he spoke for the nation, hours after Diana’s death, or the priority he placed on tackling crime and anti-social behaviour, or his dogged determination to drive up standards in schools and the NHS in the poorest neighbourhoods. In meetings, his energy was always apparent. He would usually be the best informed and most insightful person in the room, regardless of which experts were present, or which subject was under discussion.

His place in Labour’s history is assured as the leader that proved that not only could Labour win elections, but that Labour could govern. He made real our conviction that economic efficiency and social justice could sustain a governing project. There were times in the 1980s, when Labour’s future as a long-term governing party seemed remote. Now, no-one can doubt it.

Christopher Wren famously asked visitors to St Paul’s who sought his memorial to look around them. Those in search of Blair’s legacy should similarly look around them. Visit the Sure Start centres, or the new hospitals, or the new school buildings. Talk to the families with jobs and affordable mortgages. Visit the great cities of Britain – Manchester, Leeds, Birmingham, Newcastle, Cardiff or Glasgow – and see the rebirth of our city centres as vibrant centres of arts, culture and entertainment.

This is Blair’s legacy: a modern, confident Britain, with more people getting on and doing well than ever before. A country facing the challenges ahead, free from fear or trepidation. Looking forward to the Olympics. Ready for the future.

As for Tony himself – the days when a retiring Prime Minister simply shuffled off the stage to flog his memoirs are long gone. Tony Blair is a relatively young man, at the height of his powers. I have no doubt that he will make a huge contribution to public life, both home and abroad.

But there’s one last act for which we should be eternally grateful. That is Tony and Gordon’s achievement of a stable and orderly transition from one to the other. As a party, we’ve never really achieved renewal in office. Until now. Today, with the polls closing on the Tories, their policies in tatters, their leader under pressure, and their backbenchers defecting, Labour is ready for the next phase of government. Gordon Brown’s time has come. Labour faces some tough challenges. We’ve two by-elections within weeks, then London elections next year. I am sure every single one us will get behind Gordon and fight tooth and nail for a fourth Labour term.