Career criminals made up a third of serious offenders convicted in Thames Valley last year, figures reveal – suggesting many are caught up in a cycle of reoffending.
The statistics also show fewer than half of those convicted with at least 15 previous convictions or cautions to their name were sent to prison.
The Labour party said the "shocking" national figures showed the Government was "soft on crime and its causes", putting the public at risk.
In Thames Valley last year, in 1,516 of the 4,450 cases (34%) where an adult admitted or was found guilty of an indictable offence – such as theft, violence or rape – the offender had at least 15 previous convictions or cautions, Ministry of Justice data shows.
That included 44 where the offender had 75 or more previous convictions or cautions.
The figures also showed that of the cases where offenders had at least 15 previous convictions or cautions, 643 (42%) resulted in an immediate prison sentence.
Some 83 (5%) resulted in no punishment and 270 (18%) with a fine.
The outcomes for 120 cases were not specified.
Across England and Wales, the proportion of adult offenders convicted of a serious offence with 15 or more previous convictions or cautions last year was 36% – down from 38% in 2019, but above the 32% in 2010.
Of those cases last year, 45% resulted in an immediate prison sentence.
The Labour party said the "shocking" figures were partly a result of the Government's decision to part-privatise the probation service seven years ago – a move reversed in June this year with renationalisation of the service.
Holly Lynch, Labour's shadow minister for crime reduction and courts, said: "The Government is soft on crime and its causes.
"By failing to reduce crime through rehabilitation in our prisons and our communities, the Tories are putting the public at risk."
She added that Labour would "put victims first by enshrining their rights in law" and focus on criminal rehabilitation to stop the cycle of reoffending.
In its outcome delivery plan for 2021-22, the Ministry of Justice said it would stop reoffending by focusing on interventions such as providing a home, job and access to treatment of substance-misuse.
It said the reunification of the probation service meant staff had the skills to run rehabilitative programmes, preventing crime and increasing supervision of offenders outside prison.
But groups which support the rehabilitation of reoffenders say the Government was still not doing enough.
Charity Unlocked, which helps people dealing with the stigma of a criminal record, said people also needed support with physical and mental health and wellbeing, as well as housing and employment.
Chief executive Angela Cairns added: "Having to disclose a criminal record is a barrier to access those things – local authorities are permitted to exclude people with unspent convictions from social housing and more than half of employers admit they would discriminate against someone with a criminal record."
A Ministry of Justice spokesperson said: “Reducing reoffending is one of our top priorities.
"That’s why we’re investing millions through the Beating Crime Plan to provide robust monitoring, while tackling the drivers of offending such as substance misuse, homelessness and unemployment.”