Keir Starmer did not rule out using nuclear weapons if he becomes prime minister next year as he visited British troops near the border with Russia.
The Labor leader also appeared to suggest he could consider offshore processing to deal with migrants coming to the UK in small boats, saying he would “consider any credible option”.
In a wide-ranging interview, he expressed concern for his family if he moved to No 10, but said he was ready for an election in the spring.
And he said he did know the meaning of “rizz” – the newly crowned “word of the year” denoting style or glamor – but had forgotten it.
In 2015 then Labor leader Jeremy Corbyn said he would never use nuclear weapons as prime minister.
At the time he was accused of jeopardizing the UK's relationship with NATO, which is a nuclear alliance.
But visiting a NATO base in Estonia, Sir Keir did not rule out using nuclear weapons if he wins the keys to Downing Street.
Asked during an interview with GB news whether he would launch nuclear weapons to protect the UK, Sir Keir said: “The nuclear deterrent is very important to us. Obviously, I'm not going to discuss with you the circumstance in which it might or it may not be used, but it is a very important part of our country's defense that we are strongly committed to, along with our commitment to NATO and our nation's security, which is paramount.”
He said: “There has been an unwavering commitment to NATO since NATO was created, which of course was under a Labor government. …There is a real sense of purpose here with the troops who are here on the front line.”
Sir Keir said his “ambition” was to increase defense spending, adding that “when the last Labor government was in power, it was 2.5 per cent”.
He also said he had a manifesto ready “when we need it” even though the election is just 19 weeks away, to coincide with local elections in May.
Days after the prime minister said an election would be held in 2024, he added: “We are ready for a general election. I have had my whole team in a general election for some time.”
However, he admitted he was worried about the potential impact on his family, including his two teenage children.
“I'm worried about my family. To be honest, I'm very protective of my wife and our children,” he said.
“We don't name our kids in public. We don't take pictures with them. And so I'm very careful about the impact it could have on them.
“Our boy is 15, our girl is 13. Those are, you know, ages where they go through a huge change. But my goal is to continue to protect them in any way I can.”
He did not rule out looking at offshore processing to deal with asylum seekers coming to UK shores in small boats, saying he would “look at any credible option, but I think at the moment, the most important thing is to get the gangs who get paid to put people on these boats.”
On taxation, he said he would “go for growth rather than pulling the tax lever” and would seek to “reduce the tax burden”.
He also said Sunak's government had “made a mistake” after Ireland announced it intended to take the UK to court over plans to offer immunity to British soldiers, among others, who served in Northern Ireland during the riots.
Sir Keir expressed his concern that the plans had “no political support in Northern Ireland from any political party and most importantly when the victims and their families in Northern Ireland do not”.