The president of the Prison Governors’ Association (PGA) will call on the government to “stop playing politics with our prisons” and will urge Boris Johnson not to pursue an agenda of putting “more offenders in prison for longer”.

Andrea Albutt, who has governed four prisons in her 29-year career with the Prison Service, will tell the PGA conference that Johnson’s approach ignores evidence and will not reduce crime or its cost to society.

Instead, funds should be invested in creating real rehabilitative environments inside prisons and in the community, Albutt will say.

Johnson kicked off his premiership with a raft of tough-on-crime announcements, which critics branded as cynical populist electioneering. Among the moves were creating 10,000 more prison places and scrapping the automatic release of some violent and sex offenders at the midway point of their jail term.

Albutt, who was elected last year as the head of the trade union, will say: “Do not put more offenders in prison for longer, it will not reduce crime and the risk and cost to society.

“Instead, invest that money in creating real rehabilitative environments both inside prisons and in the community that can be accessed by all. This policy will have a far better chance of reducing crime and reoffending and will also help stabilise our prisons and make them effective once again.”

She will add: “Stop playing politics with our prisons. Constant changing policy on prisons dictated by whoever holds the office of prime minister and justice secretary has without a doubt contributed to the myriad of complex issues we face. Policy should always be based on the evidence of what works and should be funded appropriately.”

Albutt praised the former justice secretary David Gauke for his “sensible approach”, since shelved under his Johnson-appointed successor, Robert Buckland.

Gauke was pushing for an evidence-based approach to justice and was reportedly moving towards introducing an assumption against short jail sentences of six months or less, but Buckland and Johnson have said this will not happen on their watch.

In the last five years there have been more than 250,000 custodial sentences of six months or less, and more than 300,000 of 12 months or less. Nearly two-thirds of those offenders go on to commit a further crime within a year of being released.

Albutt will say: “England and Wales already has the highest prison population in western Europe, with little impact on reducing crime in our communities. Britain seems to enjoy locking too many people up for too long in too small a space and with too little training and rehabilitation.

“Like many other public services, the years of austerity in prisons has left a legacy which, in a nutshell, has made a significant number of our prisons universities of crime, places of despair, fear, violence and control. They do not provide the rehabilitative environment to make people better citizens and reduce the burden on society.

“We know intuitively and research shows that prison and longer sentences do not work for most. It does keep people off our streets for the period they are incarcerated, but almost all offenders will be released at some point.”

Albutt will say levels of poor physical and mental health, substance addiction and learning difficulties in prisons are high among those in custody, and to rehabilitate such criminals requires a multi-disciplinary approach.

She will say: “A key emotion in getting offenders to engage in any rehabilitation is hope for the future. For many years now we have had the ability to release prisoners at the halfway point of the custodial element of their sentence. This motivational policy helps the individual, but also helps with stability of prisons because of the element of hope it brings.

“Increasing the custodial element to two-thirds in prison will certainly punish the individual for longer, but it will not improve the level of risk the individual may pose and will certainly not reduce the level of crime in society. Potentially a shorter time on licence in the community could increase risk.”

A Ministry of Justice spokeswoman said: “This government is investing £2.5bn in 10,000 new, modern prison places and will also spend an extra £156m next year on maintaining our existing jails. This will help us respond to any rise in prison population created by the increase in police officers on our streets, along with tougher sentencing for the most serious offenders.

“We will of course make sure that all new prisons are sufficiently staffed and our officers will be better protected thanks to the £100m we are spending on new security measures across the estate.”