UK-based insurance companies are to be banned from covering the cost of terrorist ransoms, Home Secretary Theresa May is set to announce.
The government hopes firms and families will be deterred from paying ransoms if the money cannot be claimed back.
Ministers maintain that paying ransoms encourages kidnapping and it says Islamic State militants are taking hostages to fund their operations.
It is one of several measures proposed in response to the terror threat.
The UK's terror threat level was raised from “substantial” to “severe” earlier this year in response to conflicts in Iraq and Syria.
Mrs May, who will address a counter-terrorism event in London later, is to set out parts of the Counter Terrorism and Security Bill, which will be introduced to Parliament this week. The government hopes to fast-track the legislation.
A week-long police initiative – Counter-terrorism Awareness Week – involving more than 3,000 officers, has begun to remind the public how they can help fight terrorism.
More than 6,000 people at schools, universities, airports, shopping centres, cinemas and farms across the UK will be briefed by counter-terror officers.
Police officers and theatre groups will be speaking to students about the Prevent strategy, which provides practical help to people who may be drawn into terrorism.
Officers will also be providing counter-terrorism information to passengers and staff at railway stations.
For a decade, British security and intelligence agencies have tried to counter threats from individuals inspired by al-Qaeda's ideology.
They're worried that the emergence of the so-called Islamic State has made that job far harder.
Twice before – in the wake of 9/11 and 7/7 – they asked ministers for more powers.
Each time there has been a difficult debate about the balance between those powers and personal liberties.
This coming bill – which is aimed at disrupting extremist activity – will face the same questions.
Against that background, a “Counter-terrorism Awareness Week” has something of a “Dig for Victory” spirit about it as the government and security chiefs seek public support ahead of potentially controversial legislation.
But PR tactics aside, the appeal is very squarely focused on the brutal fact that the police don't believe they can do this job alone.
The Home Office says current laws criminalise terrorist financing but there has been an element of “uncertainty” about whether insurers were prohibited from paying claims made by companies and families who had met ransom demands.
The Home Office says the Terrorism Act 2000 will now be amended to make it an explicit offence for insurers to reimburse such payments.
It says it hopes the change will also discourage insured companies and individuals from making payments in the belief they would be reimbursed.
This week, the home secretary will set out various other measures, also part of the Counter Terrorism and Security Bill:
- Allowing the cancellation of the passports of suspects who are overseas, so they can only return to the UK on the government's terms
- Changes to TPIMs – Terrorism Prevention and Investigation Measures – to allow the authorities to force suspects to move to another part of the country
- Making it compulsory for public bodies like schools, colleges and prisons to work to prevent terrorism
- Forcing firms to hand details to police identifying who was using a computer or mobile phone at a given time
The Liberal Democrats said it was “good news” that the Home Office had “finally got round” to producing plans to give police powers to find out who was using a phone or computer at a certain time.
Meanwhile, Britain's counter-terrorism chief has warned that police officers alone “cannot combat” the threat of extremism.
Metropolitan Police Assistant Commissioner Mark Rowley – the Association of Chief Police Officers' national policing lead for counter-terrorism – said: “So far this year, we have disrupted several attack plots and made 271 arrests but the eyes and ears of law enforcement and other agencies alone cannot combat the threat.”
The threat posed by violent extremists has “evolved”, he said.
“They are no longer a problem solely stemming from countries like Iraq and Afghanistan, far away in the minds of the public,” he said.
“Now, they are home grown, in our communities, radicalised by images and messages they read on social media and prepared to kill for their cause.”
He said “nearly half” of those from the UK joining Islamic State, a militant group which has taken control of large areas of Syria and Iraq, were “recently radicalised and weren't previously on our radar”.
On Sunday, the commissioner of the Metropolitan Police told the BBC that four or five terror plots had been stopped this year.
Police have previously prevented on average one plot a year, Sir Bernard Hogan-Howe said.