“SPRING is here, my friends, and a new chapter begins,” a beaming Jack Layton told a crowd of wildly cheering supporters on May 2nd, after Canadians made his leftist New Democratic Party (NDP) the country's official opposition for the first time. Sadly, that chapter will now have to be written by others. On August 21st Mr Layton died at 61 of an aggressive, undisclosed form of cancer.

Although Mr Layton was diagnosed with prostate cancer in 2010, he was thought to have beaten the disease before this year's election was called in March. He suffered an unexplained hip fracture shortly ahead of the vote, forcing him to campaign with a cane that became a trademark. Mr Layton looked well during a brief parliamentary session in June. But he then disappeared from the public eye, and was shockingly gaunt and clearly seriously ill at a news conference on July 25th. He stepped down temporarily as the NDP's leader to fight a new battle with cancer, promising to be back in Parliament by September. The electoral miracle he had achieved earlier in the year was not matched by a medical one.

Mr Layton's death will add even more uncertainty to a political scene that was already in flux. The NDP was born in 1961 from an uneasy marriage between agrarian socialists from Canada's prairie provinces and a largely urban labour movement. It was historically a marginal third party, weakened both by its internal divisions and the centrist Liberals' cornering of the social-justice vote. Although the NDP's opposition to free trade won it a then-record 43 of Parliament's 295 seats in 1988, the party fell to just nine seats in the following election and struggled thereafter.

Mr Layton spent 20 years as a municipal politician in Toronto before becoming the NDP's leader in 2003. In his first three federal elections neither the Liberals nor their Conservative rivals could secure a majority, enabling Mr Layton to position the NDP above the petty political fray and define it as a source of policy ideas and compromises. The party gradually picked up seats, winning 19 in 2004, 29 in 2006 and 37 in 2008.

This year Mr Layton at last found an opening for the NDP to escape its perennial also-ran status. Voters in Quebec, Canada's second-most-populous province, had tired of debating secession and of the federal party advocating it, the Bloc Québécois. The Liberals, meanwhile, had chosen an uninspiring leader in Michael Ignatieff. The NDP courted Quebec voters aggressively, running a personality-focused campaign touting Le Bon Jack's Montreal roots, good humour and seemingly endless energy and enthusiasm for politics, people and social causes. In the rest of the country the party promised to be an alternative to the partisan bickering between the two old-line parties. Thanks to Mr Layton's strong performance in debates, the NDP surged in the polls late in the campaign and took 31% of the vote, winning 103 of 308 seats.

In its new role as official opposition, the NDP already faced two monumental tasks: resisting the right-wing agenda of Stephen Harper's majority Conservative government, and coming up with a plan to reorganise Canada's political spectrum. The party could either stay independent or pursue an alliance or merger with the Liberals, the Bloc Québécois, or the Greens. Now it must focus on the more immediate project of choosing a new leader.

Mr Layton was unique in his ability to unite the NDP's prairie and urban bases while attracting new Quebec recruits. In a letter released hours after his death, he urged Quebeckers to stick with the NDP and suggested a leadership convention in early 2012. The party has four years before the next election to find a similarly charismatic replacement.