Pre-charge bail was introduced 30 years ago, in the Police and Criminal Evidence Act 1984. It allows the police to place restrictions on arrested suspects while officers conduct further investigations to determine whether a person should be charged with an offence - or not. There is no limit on the length of time police can place someone on pre-charge bail. It is imposed by the police, at an officer's discretion, without any independent oversight and with no right of appeal.
This has led to the perversion of justice where today over 70,000 people are languishing in a form of legal limbo in England, Wales and Northern Ireland - neither charged nor free. More than 5,000 of these people have been on police bail for more than six months.
Indeed, some entirely innocent people have been left on pre-charge bail for years before their cases have been dropped or thrown out of court. This goes against the fundamental legal principles of the right to swift justice and innocent until proven guilty.
Jim Davidson, Paul Gambaccini and Freddy Starr are among the well known public figures who were on police bail for many months before the police decided to take no action against them.
Libby Purves, writing in the Times last month, noted: "I have long been concerned about the way police bail runs into years even, without charge; notably in cases of 'historic' child abuse. You can be arrested (often showily, with a dawn raid), publicly named and deprived of work and reputation. OK, you aren't 'rotting in jail' but it can be just as distressing (and far more expensive) to rot in freedom. Thousands do. Some have killed themselves."
Although not convicted of any offence, people on police bail can be subject to a wide range of onerous conditions - amounting to a form of de facto summary punishment. These include having to report regularly to a police station, which can be miles from where a person lives; and being barred from entering certain areas, which may encompass the location of their home or workplace. In some cases, they may be required to cease all contact with potential witnesses, such as family members and business associates.
Other bail conditions can include being prohibited from leaving the country, using the internet or travelling on public transport.
These restrictions may be temporarily justified in certain cases. But not when they last months and years and the person has still not been charged with any crime.
People on police bail often find the conditions imposed turn their lives upside down, physically and emotionally. The mental anguish of not knowing what will happen to them is, in itself, a form of punishment without trial. The weight of suspicion grows heavier with each day that bail conditions remain in force. Victims feel stigmatised.
It is a fundamental legal axiom that justice delayed is justice denied. The home secretary Theresa May is sympathetic to a statutory time limit on pre-charge police bail. I believe it should be a maximum of 28 days and be subject to a right of appeal to a judge in open court. To this end, I joined with 24 other public figures - including Baroness Kennedy, Dominic Raab, Caroline Lucas and David Davis - in writing to the Daily Telegraph to urge reform.
One of our co-signatories, the military author, Andy McNab, noted: "If the police want more than 28 days they should go to a judge to ask for it. If someone has done something wrong then they should be charged and if they are guilty then they should be punished. But to be left dangling is just wrong."
In Scotland, the US and other countries police bail does not exist. They either charge a suspect or, if the evidence is insufficient, the person is freed.
There is cross party support for change. It will cost nothing. Bail reform is backed by, among others, The Law Society, Howard League for Penal Reform, Telegraph Media Group, Guardian Media Group and News UK. Emboldened by this broad range of support, the government must now act now to turn Theresa May's sympathy into action.
For more information about Peter Tatchell's human rights campaigns, to receive his email bulletins or to make a donation: www.PeterTatchellFoundation.org