Ukip has refused to join Labour and the Conservatives in suspending their general election campaigns following the suspected terrorist attacks in London Bridge.
Party leader Paul Nuttall said he would continue canvassing despite Saturday's (3 June) attacks, saying suspending the campaign is "precisely what the extremists would want us to do".
It comes after at least seven people were killed and more than 48 injured when a van ploughed into pedestrians on London Bridge, with three suspected attackers then going on a knifing spree in nearby Borough Market.
The Met Police, who are treating the incident as a terrorist attack, said all three assailants were shot dead by armed officers.
The Conservatives, Labour and the SNP all said on Sunday they would suspend campaigning.
Labour leader Jeremy Corbyn said his decision to stop canvassing followed consultation with other parties and was intended "as a mark of respect for those who have died and suffered injury".
Coming just weeks after a suicide bombing at Manchester Arena left 22 dead, it is the second time politicians have suspended their campaigns in the run-up to the 8 June vote.
Ukip leader Nuttall refused to follow suit.
"With more people murdered on the streets of our capital city last night by Islamist terrorists, it is more important than ever for us to confront this evil with the democratic principles that have made this country what it is," he said.
"Our hearts go out to the family and friends of those who lost their lives last night. The courage and quick response of our emergency services have yet again saved countless lives and in the midst of such a tragedy, deserve our respect and admiration.
"It is time to start honouring our dead with more than just words. The only guarantee that will come from our choosing to stall the democratic process again will be more attacks; it is what these cowards want us to do.
"For those of us seeking to serve the people of this country, it is our duty to drive the dialogue on how best to confront and defeat this brand of terrorism. That is what UKIP will be doing today and beyond. Therefore, I refuse to suspend campaigning because this is precisely what the extremists would want us to do."
Former Ukip leader Nigel Farage added: "We cannot suspend the campaign and normal life indefinitely. We want real action from our leaders, not more hand-wringing."
Some on social media called for the general election to be postponed, given the proximity to Thursday's vote.
But Corbyn suggested he would not support such moves, commenting: "We will stand together to defend our common values of solidarity, humanity and justice, and will not allow terrorists to derail our democratic process."
Mayor of London Sadiq Khan also rejected suggestions of postponing the general election.
"The general election is taking place on Thursday," he said on Sunday morning. "I'm not an advocate of postponing."
Prime Minister Theresa May is expected to chair a meeting of the emergency Cobra group of top ministers and security officials on Sunday morning.
"This is fast moving investigation," she said. "I want to express my huge gratitude to the police and emergency services who are on the scene. Our thoughts are with those who are caught up in these dreadful events."