Always a good a good strategy to go "tough on crime" when Government failing and losing support:
www.bbc.co.uk/news/uk-54135575
Quick, easy and will in reality effect a statistically irrelevant number of offenders; to start with.
Though of course a power once won will be unlikely to be relinquished and its scope of application will grow. Though to be balanced, we did see the appalling indetermate sentence framework rolled back.
If used properly (big if) I have no problems with putting the protection of the public first agsinst the rights of those hell bent on terrorism.
But what about addressing the real issues do you actually have some prison capacity mainly:
-Incarcerating not treating mental health
-Disproportionate no of women in prison
-Criminalisation of personal drug use
-Non violent offenders (this if as Boris has said in relation to above "protection of the public" should guide sentencing)