As the U.K. conservative party leader in the mid-Blair era, William Hague was the first Tory chief not to lead the country since the 1920s. With Prime Minister Gordon Brown stumbling, the Conservatives are surging in the polls. Hague, now shadow foreign secretary, would take over that portfolio if Conservatives win the next election. In New York to promote his new book on antislavery crusader William Wilberforce (the subject of the recent film "Amazing Grace"), Hague spoke to NEWSWEEK's Adam B. Kushner. Excerpts:

KUSHNER: What ' s your read on Gordon Brown? Is Labour ' s decline irreversible?
HAGUE: I hope so [laughter]. I have spent so many years banging my head against a brick wall. Suddenly the wall's collapsed! Something important happened in British politics in May 2008, I think, with three sets of elections really showing a straightforward switch of large numbers of people from Labour to Conservative.

This last month has made us conscious that we really do have to be ready to be the government. This is for real.

What happened? Is there an ideological shift in the U.K., or it just disillusionment with Brown?
When any government has been in office for more than a decade, its mistakes start to catch up with it—with a vengeance in more difficult economic times. And the prime minister himself is associated, having been chancellor of the Exchequer. And the [Conservative] party has changed: it's becoming more broadly based, it's more open to women, to ethnic minorities. Despite the ridiculous efforts of Labour in the recent by-elections to say it's a party of toffs, it's quite a classless party. Maybe the emphasis that the party gives to different issues has changed—for instance, on public services, health, education, transport systems.

How would Conservative foreign policy be different than under the Brown government?
We start from the standpoint that a nation benefits from continuity between administrations and from cross-party support, so we're not looking for things that define us differently in the foreign-policy area. There's a huge amount of common ground on Darfur, Zimbabwe, our approach to China, Russia. The most obvious difference is on European policy. We are opponents of the Lisbon treaty, currently in its ratification process. We think there should have been a referendum; we think it will lack democratic legitimacy if there was no referendum. We're skeptics about political integration in Europe; we think in many respects it's already gone too far—although we are enthusiasts of European cooperation on the single market, on trade, on relations with Russia.

How would you roll back European ties?
The area of social unemployment policy, and the agricultural and fishing policies, which have been ruinously expensive and have contributed to higher food prices in the world. The whole area of justice and home affairs, which we think should be a matter for individual nations.

Conservatives are turning green all over Europe. Are you in line with Labour now?
The Labour government is trying to make [long-term] targets for carbon-emissions reductions, and we want annual targets. Conservatives are setting the pace on environmental issues.

Are U.S. Republicans woefully behind?
There has been some change of thinking from the Bush administration. When we started on this, I did find some Republicans rather surprised. Al Gore has been to speak to us in the shadow cabinet. He's actually given us presentations, which we've found quite compelling, and I take my hat off to him.

In a national election—and this is probably true of most countries most of the time—the top issues will be schools, level of taxes, the amount of crime, health care. The environmental issues will be more important than ever before, but not quite on the level of those issues.

Some American conservatives say John McCain ' s not the genuine article.
The thing about conservatives is that they are different in every country. Socialists can have a meeting of a socialist international and have the same abstract principles, and they're all wrong together. But conservatives are based on habits and intuitions of their own country. The fact that American conservatives are "Republicans" underlines how different they are [laughter]. We are monarchists!