Mike Hobday has been at the forefront of two of the most successful campaigns of the past 10 years.First, at the League Against Cruel Sports, he led the drive to ban fox hunting. Then, at Macmillan Cancer Support, he helped persuade the previous government to introduce free prescriptions for cancer patients - a decision that helped 150,000 people.
He currently leads the campaigns, policy and public affairs team at Macmillan, which now campaigns, among other things, for cancer patients to have easier access to benefits and reduced car parking fees at hospitals.
"Throughout my life there has been a series of causes I have been interested in and people have paid me a salary to do it," says Hobday, 46, who began campaigning as a 17-year-old Labour Party organiser. "It's the most enormous privilege."
Politics is his other passion - he stood unsuccessfully for Labour in Welwyn Hatfield at this year's election, and he believes campaigning and politics are intrinsically linked.
"There are two things that you can do to create a better society," he says. "One is to have a government driving progressive change. The other is to have a voluntary sector to pressure the government and keep it honest. You can't move forward effectively unless you have both."
During the hunting campaign, Hobday was often sworn at and a dead squirrel was posted to the LACS office. "If you are going to change the way the world works, you can't do that without causing a degree of concern and unhappiness," he says.
He thinks the hunting campaign succeeded because LACS coordinated MPs to put pressure on Downing Street, which initially favoured regulation rather than a ban.
The cancer prescription campaign involved a combination of raising awareness and lobbying politicians, both nationally and locally.
Despite the different approaches, he says campaigning generally follows the same formula: set a target, identify whom you need to influence, develop a message and then create channels and opportunities to pursue your goals.
But campaign success is often elusive until the last moment. "It's like continually pushing uphill and suddenly you get to the top - but you never see where the top is," he says. "Even the day before Gordon Brown's announcement on free prescriptions, we didn't know that we were about to win."
Referring to Macmillan's current campaign to reduce hospital car parking fees, he says cancer patients visit hospital 53 times on average. It's a powerful figure with which to bombard politicians.
Hobday says his "impatience to change the world" keeps him keen. The role of campaigning, he says, will increase as spending cuts take effect.
"It will become more difficult to do everything charity beneficiaries need doing," he says. "Therefore the role of charities to leverage the system to their advantage will be incredibly important."