Jeremy Corbyn has branded Boris Johnson the “world’s leading sycophant” to Donald Trump.
The Labour leader has made the accusation as the US president is due to arrive in the UK for a NATO summit on Monday.
Trump will spend two days in the country, meeting the Queen at Buckingham Palace and other world leaders at the summit in Watford.
It is thought Johnson and Trump will hold a joint press conference also as the campaign for the December 12 general election enters its final stretch.
Making a speech on foreign policy in York, Corbyn accused Johnson of being too close to the president, saying it was “time to stop clinging on to Donald Trump’s coat-tails”.
“Boris Johnson has been the world’s leading sycophant towards the president,” he said.
He continued: “Britain must make its own foreign policy free from a knee-jerk subservience to a US administration which repudiates our values.”
Corbyn also paid tribute to the work of the emergency services who responded to the terror attack at London Bridge on Friday, and said cops who shot Usman Khan did what was right to protect the public.
“I will always do whatever is necessary and effective to keep our people safe,” he said. “First of all, the police who put themselves on the line to protect us will have the authority to use whatever force is necessary to protect and save lives.
“If police believe an attacker is wearing a suicide vest, then they are right to take the action that they do and did.”
He said people cannot be protected “on the cheap”, but added: “We have to understand that no government can prevent every attack. No-one would believe any political leader who said they could. But the government can act to make such acts of terror less, rather than more, likely.”
It comes as Johnson accused the last Labour “leftie” government of bringing in early prisoner release legislation which allowed Khan, who was jailed in 2012, back on the streets.
But others have pointed out that Khan had appealed an indeterminate imprisonment for public protection (IPP) sentence in 2012. The Coalition later scrapped these sentences and Khan successfully launched an appeal to have his sentence cut.
Johnson also pointed out on BBC One’s Andrew Marr Show that the Conservatives were pledging £2.5bn of investment in the Ministry of Justice.
Setting out how his approach would differ Johnson’s, Corbyn said: “I will be a very different kind of prime minister: one who is prepared to limit my own power in the public interest and empower parliament to hold government to account.”
The Labour leader also reiterated his opposition to the Iraq War and said his party would end arms sales to Saudi Arabia for use in Yemen.
Corbyn ended his speech talking about patriotism, stating: “Patriotism is about supporting each other, not attacking somebody else. It’s about caring for the whole of society, for all our people, and not walking by on the other side when they need help and support.
“It’s about loving your country enough to make it a place where nobody is homeless or hungry, held back or left behind.
“On the international stage, it’s about standing up for the values we share of justice, human rights and democracy, and working with others to keep people safe, by ending conflict and tackling the climate emergency.”