Extremists face having their sentences lengthened under a widening of a scheme that allows the public to challenge penalties handed down by courts.
Ministers confirmed plans to add 19 further terror-related offences to the Unduly Lenient Sentence scheme which allows victims and members of the public to ask the Attorney General to examine sentences they believe to be very low or unduly lenient.
The move means crimes including encouraging terrorism, sharing terrorist propaganda and belonging to banned organisations will now be covered by the programme.
Cases are reviewed and can be sent to the Court of Appeal, which will then determine whether the sentence should stay the same, or be increased.
Calls for the ULS scheme to be extended emerged last year after the cleric Anjem Choudary was jailed for five-and-a-half years after he was convicted of inviting support for Islamic State.
The new measure, which was first announced last year, will be formally introduced in a statutory instrument on Monday, before taking effect on August 8.
Justice Minister Dominic Raab said: "We want the most robust sentences for any terrorist crimes and for victims to have every opportunity to see justice delivered.
"Our action will reinforce our focus on deterring people who help radicalise terrorists, and punishing those who wilfully turn a blind eye to terrorist activity."