For American prisoners the wait for execution can be a long one – 16 years is not unusual – and this delay has attracted the interest of British barristers opposed to capital punishment.

Privy Council barristers who have defended prisoners sentenced to death in the Caribbean feel they have gained invaluable experience which can be applied to the US system. They are also well versed on important points of international law.

But the real breakthrough came in Trinidad in 1994. In Pratt and Morgan, Geoffrey Robertson QC, the leading anti-capital punishment lawyer in the UK, argued a case in Trinidad which was to be a turning point. The Privy Council decided that prisoners held on death row for more than five years were under extreme pressure and that this was punishment enough. It argued that in such cases the death penalty should no longer be enforced.

The chairman of the Bar Human Rights Committee, Nicholas Stewart, says: “We felt that our experiences with the problem of people being on death row for a long time meant we had a good contribution to make on an important matter of principle.”

The case caught the attention of American lawyers who spotted the opportunity to get their English counterparts over to argue the point of international law relevant to cases in the US.

Julian Knowles, an English barrister, has worked for the Oklahoma and Florida Death Penalty Centres to defend condemned prisoners. “Lawyers go out there because within the American context executions are very routine. They do not get any publicity,” he says. He remembers a hairdresser in Florida, hearing what work he did, then asking if Florida had capital punishment.

Knowles has devoted time to the problem of death row syndrome and believes British lawyers involved in such cases have a dual role. “When English lawyers go to America it serves two purposes, the legal one and to raise publicity for the case.”

The most famous recent death row case is that of Krishna Maharaj, a Trinidadian-born fruit importer, who was convicted in 1987 of the murder of two business associates in a Florida hotel room.

Maharaj has always maintained his innocence. He points to a number of inconsistencies in the case against him and claims he did not receive a fair trial because the judge was arrested on corruption charges four days into the hearing.

Last year the Florida Supreme Court granted Philip Sapsford QC and Geoffrey Robertson QC rights of audience to plead on behalf of Maharaj, who has now spent nearly nine years on death row.

Both barristers had valuable experience working before the Privy Council. In Barbados, Robertson successfully defended death row prisoners Peter Bradshaw and Denzil Roberts in 1985 and 1986.

But British lawyers are not challenging the right of US states to impose the death penalty. As in the Caribbean cases, it is the length of time that the condemned men are forced to wait on death row that they are attacking.

In 1994, when the Bar Human Rights Committee sent lawyers to Texas, they found 380 men and four women in prison awaiting execution. They reported that in recent years the average time a condemned person had spent on death row before being executed in Texas was 8.2 years and the longest over 16 years.

And it is not only UK citizens who can receive help from British lawyers. “A British connection may be a factor but not necessarily,” says Stewart. The Bar Human Rights Committee operates on a broad basis and tries to get involved in non-British cases.

David Marshall QC works closely with Clive Stafford-Smith, an English lawyer based in Louisiana. He agrees that the involvement of British lawyers helps. “The American legal committee still has a great deal of respect for the English bar,” he says. “The fact that they are coming from the UK is a very effective way of raising the profile of such cases.”

Marshall believes the way ahead is to get young American lawyers interested in the work so that the original trials can be fairer. “It is very difficult to get the original conviction overturned,” he says. “If you can get an effective trial counsel you are more likely to get an effective trial. That is the most important level to get involved at.”

The history of defendants being allocated inexperienced and uninterested lawyers during their trials is well-documented. There are stories of lawyers falling asleep during trials or failing to continue to defend their client when the money runs out. Even a third-year law student who had never been in a court before has been known to represent a defendant on death row. “If the circumstances weren't so serious it would be hilarious,” says Knowles.

Despite recent changes in the way the US system operates, which has seen the closure of Death Penalty Centres, many lawyers still take up cases on a private basis and they are paid by the federal government case by case. They can then call on the help and advice of English lawyers. But the cost of lawyers going to America can be high and the problem of funding restricts the amount of work they can do.

Marshall says money is cobbled together from various sources. “Cash comes from lawyers' own backs, the Human Rights Committee or groups supporting the man on death row,” he says. In the Maharaj case Robertson paid most of the expenses from his own pocket.

Stafford-Smith, who defended the since executed Briton Nicholas Ingram, said in reaction to the federal government's decision last summer to cut off all funding for appeals in capital cases: “We desperately need to come up with some funds to pay half-a-dozen more lawyers who care enough to fight for the retarded, the children and the innocent. We need volunteers to give their energy and their charity to do what we can to help as many of the condemned through their dark times as we can.”

His appeal has not gone unanswered, and English lawyers dedicated to human rights are prepared to persevere against injustice at their own expense. They do sometimes meet opposition from Americans who believe they are wasting their time and that the issues are for the US to deal with. But Julian Knowles disagrees.

“The death penalty is a human rights issue. Opposition is something you just have to deal with but it is an international issue not a domestic one. There are protections that all countries should observe. Whatever you think about the death penalty, everyone is entitled to a fair trial and fair representation.”

Delegates can attend 'Deadman Walking, Due Process and the Death Penalty' at the conference on 4 August.