She pointed to longer jail terms for terrorism offences, even minor ones, and said internet companies should deny extremism.
After seven people were killed in central London on Saturday, less than a fortnight after 22 concert-goers were slain by a suicide bomber in Manchester and two months after five were killed in another attack in Britain's capital, Prime Minister Theresa May declared "enough is enough" and sketched plans for tougher anti-terror measures.
She pointed to longer jail terms for terrorism offences, even minor ones, and said internet companies should deny extremism a place in which to breed.
Other proposals floated in the British press include electronically tagging or even interning jihadists on watch lists, requiring proof of ID for unregistered SIM cards for mobile phones, and police background checks for people who want to rent a car immediately.
But after a one-day suspension of campaigning ahead of Thursday's vote, May's record has become a hot election issue and the ruling Conservatives -- traditionally popular on the issue of security -- find themselves on the back foot.
Labour leader Jeremy Corbyn on Monday called on May to quit, pointing to the loss of 20,000 police jobs, mostly during her six years as interior minister under David Cameron.
Labour has promised to recruit more police officers, adding to neighbourhood security that it sees as an essential element for counter-terror strategies.
Asked by ITV television if he backed the calls for May to resign, Corbyn said: "Indeed I would... We should never have cut the police numbers."
Mark Garnett, a lecturer in politics at Lancaster University in northwest England, said Corbyn was trying to hit a sweet spot with just three days left before voting day.
"From Mrs May's point of view, it's very difficult for her to suggest anything radically different because of course she's been in charge of security policy for the last seven years, either in overall charge or as home secretary," he said.
"I think she's absolutely under terrible pressure."
Outside the political arena, commentators say tackling Islamic radicalisation is a delicate challenge, and electioneering could have unwanted consequences.
"If you intervene in Muslim communities, you may actually radicalise people. But if you don't intervene in Muslim communities, then you may actually allow people to be radicalised," said Steven Fielding, a professor of political history at Nottingham University.
Tougher laws and police powers may fail to prevent low-technology attacks, such as the two van-and-knives assaults that occurred in London, and may well end up alienating British Muslims, he said.
Britain already has a long roster of security tools, headed by so-called Terrorism Prevention and Investigation Measures, or TPims.
Introduced in 2012 and toughened in 2015, TPims apply to people who are deemed a threat but cannot be prosecuted or, in the case of foreigners, deported.
They grant the authorities the ability, lasting initially for one year but which can be extended to two, to implement a form of house arrest and relocate a subject up to 200 miles (320 kilometres) from their normal residence.
In November last year, lawmakers granted sweeping surveillance powers for the police and intelligence services.
Among other things, the law requires websites to keep customers' browsing history for up to a year and gives legal footing to existing, but murky, powers such as the hacking of computers and mobile phones.
The rights watchdog Liberty denounced it as a "snooper's charter" that authorised "totalitarian-style surveillance powers".
Fielding pointed to a scheme called Prevent, set up after the July 2005 London bombings, which promotes grassroot anti-radicalisation programmes among Muslim communities.
"A lot of people are saying, this is actually the way to go, but it's very difficult to do and very under-resourced as well," he said.
"It's very easy to say in front of No. 10, 'enough is enough,' but when it comes to precise measures, you might make things worse. And it's very easy to say, 'We need more police on the street because that might have stopped some of these things,' but -- really -- would it?"
Radicalisation "is a very difficult and complex social issue that doesn't lend itself to electioneering campaigning and sloganeering, but this is where we are."