Security services are preparing to monitor dozens of terrorist offenders, reveal sources

Many extremists who were jailed over terror incidents are set for release in the next 12 to 14 months, writes defence editor Kim Sengupta

Police officers conduct a search in south London after the Streatham attack last month (AFP/Getty)

Britain’s security agencies are making contingency plans for dozens of inmates convicted of terrorist offences coming out of prison in the near future even if laws are brought in to delay early release.

The government has announced plans to extend the time for the release of the prisoners from half to two-thirds of their sentence served in custody following the attacks by Usman Khan and Sudesh Amman after they had been freed early.

However, a sharp rise in terrorist investigations with the rise of Isis and subsequent trials in the last decade has meant that a significant number would have served their sentence, and become entitled to leave custody, within the next 12 to 14 months.