In what could be regarded as the most significant break in the foreign policy narrative of Britain’s largest political parties, Labour leader Jeremy Corbyn has launched a scathing attack on Britain’s track record, arguing that its approach had failed to promote peace at home.

“Seeing the army on our streets is a stark reminder that the current approach is not working very well,” Mr. Corbyn told a gathering in central London, as parties resumed their campaigning days after the attack on the Manchester Arena, which killed 22 people and injured well over a 100.

In a passionate speech, which began with a minute’s silence for the attack’s victims Mr. Corbyn said that while the blame for the atrocity lay with the terrorists alone, protecting the country in the long term required an informed understanding of the causes of terrorism.

“No rationale based on the actions of any government can remotely excuse, or even adequately explain, outrages like this week’s massacre… but we must be brave enough to admit the war on terror is not working,” he said. “We need a way to reduce the threat from countries that nurture terrorists and generate terrorism,” he said.

A Labour government would focus on strengthening national security, and would only deploy troops abroad if there was a clear need and a plan, adequate resources and a focus on delivering an outcome that delivered lasting peace, he promised. While no government could prevent every terrorist attack, it was the responsibility of government to minimise that chance, and ensure that foreign policy reduced rather than increased the threat at home, he said.

Critical of funding cuts

Mr. Corbyn was also critical of cuts that had been made to emergency services, pointing out that both forces had been key to the response in Manchester. “Austerity has to stop at the Accident and Emergency ward and at the police station door. We cannot be protected and cared for on the cheap,” he said, pledging to increase the number of police on the streets and more resources for security services should they need them.

While his words are a clear attack on the Conservative government’s foreign policy they are also a criticism of past Labour policy. Mr. Corbyn strongly opposed the Tony Blair government’s intervention in Iraq and Afghanistan.

The police in Britain have thwarted 18 terror plots in the past four years alone.

The attack on Manchester has left the UK government vulnerable to criticism on a number of counts, including resources made available to police forces. Home Secretary Amber Rudd was on Thursday, forced to deny that a lack of resources had undermined their ability to gather intelligence on threats.

A poll by YouGov following the Manchester attack found that the Conservatives’ lead had slipped further to 5 points from 9 points.