Sebastian Coe, the double Olympic champion who led the organising committee of London's 2012 Games, has been elected as the president of the world governing body for athletics.

Ahead of the world championships in Beijing and against a backdrop of doping allegations that have brought the sport to its knees, Coe defeated Ukrainian former pole vaulter Sergey Bubka and will now be tasked with restoring the reputation of the sport.

Thirty-four years to the day after he broke the world mile record in Zurich Coe won by 115 to 92 of the votes on offer to become president of the International Association of Athletic Federations and will now automatically also become a member of the IOC.

Afterwards Coe said that winning the IAAF presidency ranked above winning Olympic gold or delivering the London Olympics in terms of momentous moments in his life.

“I think for most of us in this room we would conclude that the birth of our children are big moments in our lives and probably the biggest,” he said. “But I have to say that the opportunity to work with all of you and shape the future of our sport is probably the second biggest and momentous decision in my life.”

The former Tory MP, who has been an IAAF vice president since 2007, takes over at a crucial juncture.

As part of his manifesto, he has promised more resources for anti-doping and an independent unit to avoid allegations of conflicts of interest. He has also promised to overhaul the athletics calendar, better promote the sport and make it more relevant to young people.

Coe, who becomes just the sixth president of the IAAF in its 103-year history, has also promised to deliver $200,000 in development funds to every member association across each four-year cycle.

But by far the biggest challenge he faces is to restore public confidence in the sport in light of the latest doping allegations.

By declaring that recent doping allegations amounted to a “war” on athletics he sought to appeal to the voters who held his fate in their hands but sparked criticism at home.

Before the vote, Coe made a final pitch to the members. “It goes without saying this is a big moment in the history of our sport. It is also, I may add, a big moment for me personally,” he said. “After so many races run, this might be my last race. The decision lies with you. I stand here humbly offering my service to athletics.”

He vowed: “There is no task I have been better prepared for. There is no job I have ever wanted to do more and to do with greater commitment. If you place your trust in me I will not let you down.”

Coe's victory means there are now British presidents of the world governing bodies at the two sports most heavily linked with doping in the public mind - Brian Cookson took over as president of cycling's world federation last year. Sir Craig Reedie, the British IOC member, is also president of the World Anti-Doping Agency.

The IAAF's travails were demonstrated by the fact Valentin Balakhnichev, the former Russian federation chief who was supposed to have stepped down in wake of doping claims in February, appeared on stage to present the organisation's financial report.

Bubka had earlier promised to show “zero tolerance” to doping and said his most important priority would be developing the sport around the world. “My doors, my heart will always be open. We will bring athletics to new heights,” he promised in his speech before the vote.

Coe had claimed to have travelled 700,000km in a bid to woo voters since his candidacy was announced late last year.

Bubka, in contrast, has waged a low key campaign. His manifesto pledges mirrored many of Coe's and he instead relied on the loyalty and links in Africa, Asia and South America that he had built up over the course of 14 years involved at the federation.

Coe turned down overtures to become BBC chairman and to enter the race for the London mayoralty as a Tory candidate in order to focus on leading his sport.

The election brings the curtain down on the controversial 16-year tenure of the Senegalese president Lamine Diack. He believes that he has helped spread the global appeal of the sport, taking the world championships to Daegu, Moscow and Beijing.

But that period has also been marked by controversy,with doping revelations that have built to a crescendo on the eve of the world championships.

Late last year, an independent IAAF ethics commission chaired by Michael Beloff QC began investigating allegations of systemic doping by the Russian athletic federation and wider claims of corruption and cover up.

Eight months later, it has yet to report but is expected to do so shortly after the world championships.

In his final speech, Diack defended the IAAF’s record on anti-doping and claimed that the sport had been “turned into a kind of monster in the eyes of the newspapers which seem to be saying that everyone takes drugs”.

But he said that the IAAF had led the way in new methods of testing and arguing for stronger bans for athletes. “Everything that has been done in anti-doping in sports comes from athletics,” he claimed.

Alluding to cases such as that of Justin Gatlin, the twice banned American sprinter who is one of the favourites for the 100m title, Diack said it was inevitable that it would happen until such time that lifetime bans were introduced.

Last week 28 athletes from the 2005 and 2007 world championships were banned after their samples were tested, while on Monday the London 2012 Olympic 1500m champion Asli Cakir Alptekin was stripped of her gold medal and given an eight-year ban after abnormal values were found in her blood samples.

(Guardian Service)