Video: Cooper says rival Corbyn has ‘wrong answers’ and lacks radicalism

The shadow home secretary insisted a “more feminist approach” is needed for the economy to ensure work fits around families as she attempted to pitch herself as the radical and credible candidate.

Speaking in Manchester, Ms Cooper said she did not dismiss the values and intentions of veteran left-winger Mr Corbyn and his supporters.

But she said she would not “pander” to them either and claim to be a “more electable version” of what they stand for.

Ms Cooper, who accepted her attack may lose her votes, said: “Because the truth is that Jeremy is offering old solutions to old problems, not new answers to the problems of today.

“We have to look the 21st century in the eye, face up to the future - that’s where we will find the new radicalism, the answers in the modern fight for social justice, for equality and for solidarity, not in the old answers of the past.

“I understand Jeremy has strong support. But I feel really strongly, not just as a leadership candidate but as a Labour Party member that desperately wants an effective Labour government, that his are the wrong answers for the future - that they aren’t radical and they aren’t credible.

“And they won’t change the world, they will keep us out of power and stop us changing the world.”

Ms Cooper added: “And what is more radical? Is it a Labour Party, after a century of championing equality and diversity, that’s going to turn the clock back to be led again by a leader and a deputy leader who are both white men?

“Or is it to smash our own glass ceiling and to get Labour’s first elected woman leader and first woman prime minister. Who is really the radical? Jeremy or me?”

The leadership candidate made the set-piece speech as the attacks on Mr Corbyn’s campaign intensified in what is viewed as a sign of increasing concern at his status as frontrunner.

Tony Blair made another intervention in the contest by claiming the party risks “annihilation” under Mr Corbyn.

The former prime minister warned Labour could fail to be in government again and is in “danger more mortal” today than at any point in its existence.

Mr Blair, writing in The Guardian, directed his remarks at long-standing members and called on them to “save the party” and heed his warnings regardless of whether they used to “support me or hate me”.

Labour Party data shows more than 600,000 people are set to choose the next Labour leader, with the latest figures including 299,755 members, 189,703 people from bodies affiliated to the party - such as trade unions - and 121,295 people who have paid £3 to register as a supporter.

The surprise emergence of Mr Corbyn has led to calls for it to be re-run over allegations that it has been exploited by hard-left groups and political opponents including Conservative activists.

Labour said it has already excluded 1,200 members or supporters of another party and will continue to verify those signed up and remove people who are not entitled to a vote.

Ms Cooper continued: “We can’t just luxuriate in our own righteousness out on the sidelines.

“That’s not a luxury the most vulnerable in Britain can afford.

“It’s not enough to be angry at the world. We’re the Labour Party, we have a responsibility to change the world or what’s the point of us at all?”

Ms Cooper said the real radical approach is to reform capitalism so it serves people, “not to try to destroy it with nothing to put in its place”.

She continued: “And we need what is, bluntly, a much more feminist approach to our economy and society.

“Put family at the centre of our economy. As any parent will tell you, that would be really radical and it would transform families’ lives.

“Stop families being stretched and stained to fit round work, and change work to fit round family life.

“Universal free childcare should be as much the infrastructure of the modern economy as trains, planes and boys toys.”

Ms Cooper also attacked Mr Corbyn’s foreign policy approach.

She added: “Is it really radical to quit Nato, to prevaricate over membership of the EU, or trash our reputation as an internationalist party.

“I say no.

“We should stay in the EU, stay in the European Court of Human Rights, stay in Nato - sorry, Jeremy, internationalism is a core Labour principle and I will always fight for it.”

Ms Cooper said she agreed with Mr Corbyn about the need for an alternative to austerity and not to “swallow the Tories’ myths” about Labour and the deficit, but the alternative needed to be “credible”.

She said Mr Corbyn’s plan of “quantative easing for the people” was “really bad economics”.

She added: “It won’t stand up to scrutiny. And it won’t get us elected.

“And that matters. Because otherwise we let people down.”

But she offered party members hope that power can be wrested from a “narrow Tory elite” running the country.

She concluded: “They only have a majority of 12. We can beat them.

“So this is the choice.

“Between a Labour Party back on its feet, fighting the Tories, fighting for our principles, fighting for our future

“And a Tory Britain while Labour walks away.

“This is about the 2020 election.

“I’m in it to win it. The Labour Party must be too.”