Tighter controls on the movements of paedophiles have been announced by Home Secretary Jacqui Smith.
Measures include increasing the length of time child sex offenders can be banned from travelling abroad from six months to up to five years.
Ms Smith said the changes would bolster the UK's already "rigorous system" for managing sex offenders, which is "among the toughest in the world".
It comes as paedophile and ex-pop star Gary Glitter left a Vietnamese jail.
He was released on Tuesday after serving 27 months in prison for child molestation.
The 64-year-old, whose real name is Paul Francis Gadd, was convicted in 2006 for molesting two Vietnamese girls aged 11 and 12.
The home secretary announced that the length of Foreign Travel Orders (FTO) for paedophiles would be increased from six months to up to five years.
FTOs are civil orders developed to restrict travel by UK-registered sex offenders.
And she said the requirement on police seeking sexual offences prevention orders to provide evidence from the last six months will also be removed.
Under the changes, those subject to blanket travel bans will also have their passports automatically confiscated.
And there will be a consultation on further restrictions on paedophiles' passports.
It also emerged that FTOs may also be available where children under 18, rather than under 16 at present, are in danger.
The home secretary said: "I want to see anyone who poses a threat to our children dealt with as firmly as possible.
"I've spoken to child protection experts and the police and they have told me that these changes will further restrict the ability of child sex offenders to harm children both here and overseas."
Only five foreign travel bans for sex offenders have been issued under the current system, compared with 3,000 for football hooligans.
Asked on BBC Breakfast if enough foreign travel orders were being issued, Ms Smith said: "I don't think there are enough issued at the moment - I think there is more that we can do to prevent people from travelling abroad.
"What police and others say to me is that one of the reasons that they don't apply for them is because they only last for six months. I think we can extend that time period."
The Home Office revealed that legislation will shortly be brought forward to introduce new powers where necessary.
Meanwhile, children's campaigners have welcomed the measures.
NSPCC policy advisor Zoe Hilton said these measures "are a crucial step forward and should help clamp down on sex tourism".
She said: "We have been consistently saying that when there is clear evidence a sex offender poses a risk, the authorities must have effective powers to stop them from going abroad.
The announcement comes just days after children's charity Ecpat UK published a report calling for an overhaul of the way Britain deals with nationals convicted of sex offences abroad.