Amid growing incidents of British teenagers travelling overseas to join ISIS, Prime Minister David Cameron on Monday unveiled tough new measures, allowing parents of teens at risk of "poisonous" radicalisation to have their passports blocked.
The new rules announced by Cameron also include a full review of all public institutions in the country to safeguard them against infiltration by extremists, including schools, colleges, the civil service and local authorities.
More parents will be able to ask for their children's passports to be cancelled if they fear they could go overseas to join terror groups. The power already covers under-16s, but will be widened to 16 and 17-year-olds.
"The government's new Counter-Extremism Strategy is a clear signal of the choice we have made to take on this poisonous ideology with resolve, determination and the goal of a building a greater Britain.
"And a key part of this new approach is going further to protect children and vulnerable people from the risk of radicalisation by empowering parents and public institutions with all the advice, tools and practical support they need," Cameron said.
Families can contact a passport office where officials will investigate their concerns before a final decision is taken by UK home secretary Theresa May.
As part of the new measures, anyone with a conviction for extremist activity will also be automatically barred from working with children and vulnerable people under the plans.
Cameron added, "We know that extremism is really a symptom; ideology is the root cause - but the stakes are rising and that demands a new approach.
"So we have a choice - do we choose to turn a blind eye or do we choose to get out there and make the case for our British values."
"If you talk to, as I have, parents of young people who have been on the path to radicalisation, or perhaps parents, as I have heard from, who have children who have gone out to Syria, some of whom have died out there fighting, then they are saying that they want to see more action taken," May told BBC.
"I'm not pretending that any of this is easy. Of course this is difficult, but government has a choice here. We can either say 'well, this is difficult so let's not do anything' or we can say 'well, actually it is difficult, but this is so important that we need to take action'," she said.
According to the latest police figures, of 338 counter-terrorism-related arrests, 157 were linked to Syria and 56 were of people aged under 20, it said.