Britain could become a safe haven for child sex offenders seeking to evade justice in the event of a no-deal Brexit, the NSPCC has warned ministers.

The charity has written to Sajid Javid, the Home Secretary, who has made the fight against child abuse a top priority, warning that the loss of EU agreements on extradition and arrest of child sex offenders would prevent police bringing them to justice as quickly and easily as they do now.

It says the European Arrest Warrant (EAW), introduced in 2004 after the 9/11 terror attack, has enabled police to capture and then extradite wanted sex offenders within days.

Before its introduction it could take a year to bring a child sex abuser to justice whereas now a wanted offender can be surrendered to a prosecuting country within 14 days, where the person consents, according to figures obtained by the NSPCC.

Even where the offender fights the EAW and extradition, it still takes just two months on average.

In its letter also sent to the Department for Exiting the EU, it says that without similar measures in place post-Brexit, sex offenders would see Britain as a “soft touch” to evade justice in other countries or flee Britain if they had abused a child here, knowing it would be harder to extradite them.