Of the four men who took up the great offices of state in May 1997, only one is no longer with us.

 While Gordon Brown, Tony Blair and Jack Straw  have all been aged by office, New Labour’s first Foreign Secretary Robin Cook’s life was tragically cut short in 2005 when he suffered a heart attack while on a walking holiday in Scotland.

 It’s easy to get nostalgic about those who are no longer with us because their memory remains untainted. Lost heroes are easier to revere than living, breathing, human ones.

With Cook however, the regret and sadness seems historically justified. His most famous act as a politician was to resign as Leader of the House to take a difficult, but correct, stand on the 2003 Iraq War.

What is striking about his resignation speech though is its lack of moral righteousness. Even when telling his government colleagues he believed they were catastrophically wrong he did not impugn their character.

Cook’s argument was not that military interventions are always wrong, but that they should be a last resort and be carried out with broad international agreement.

His principles forced him to resign from Tony Blair’s government, but they were also why he still believed in it.

It was the speech of  a man who his friend, Lord Kinnock, describes as possessing, “originality of mind”, “political guts” as well as, even when rebelling, “loyalty”.

Politicians will always be defined by their actions in particular moments. We remember the dazzling speech or disastrous error. But glories are almost always the result of years of hard graft.

Few grafted harder than Cook - one of the generation of Labour MPs who spent 18 years in opposition before they tasted ministerial office. Without power they had to console themselves with moral victories and holding Tory governments to account.

One such moment in Cook’s career is still instructive today. His response in 1996 to the publication of the Scott report into arms sales to Iraq  has passed into parliamentary folklore. Despite only being given two hours in a locked room to scrutinise the 1806 page report he forensically dismantled the Tory government’s position and inflicted another of the many Tory wounds that would contribute to 1997’s landslide win.

His adviser at the time, David Clark, says that his response was the result of years of studying the issue

“The reason he was able to extract the most damaging information in time to savage the government in the Commons later that day is that he had done his homework,” he explains. “By the time they locked him in that room, he already knew what he was looking for.”

The joy of victory was a result of years of hard work.

In government, Cook’s pronouncement that Britain should have an “ethical foreign policy” often made things awkward for him, but is one reason he is remembered so fondly. It’s a phrase that speaks to the hope many had in 1997 that in Labour they would have a government that combined compassion with competence.

Looking back from the present, when he died Labour lost more than a great parliamentarian. It lost someone who embodied the left’s need to combine a radical heart with a pragmatic and restless intellect.

Asked what he thinks his old boss’s advice would be to Labour supporters today, Clark adds, “Don’t lose yourself in the search for power, and don’t lose sight of the need for power in the search for ideological purity. Above all, don’t succumb to bitterness and despair.”

Cook’s qualities are needed now more than ever. We all know 2017 will be a difficult year for Labour, as even a remarkable victoriy won’t heal the divisions that have become painfully obvious since 2015.

In the forthcoming election and beyond though it is hard work, intellectual rigour and generosity, even in disagreement, that will rebuild Labour and the left so a new generation of Labour politicians can begin their journey in government.

 Mark Worgan is a Young Fabians member. Follow him on Twitter at @worgztheowl