Asylum-seekers coming to the UK cannot always present a case which is clear-cut - and often face an appeals process lasting many months.

Home Secretary Jack Straw says he will speed up the decision-making on the Afghan hijackers and those hostages claiming refuge in the UK.

But as the number of asylum requests already under consideration is rising, there can be no guarantees of a swift decision on their fate.

Anyone who arrives in the UK as a political refugee is likely to go through the following steps:

Firstly he or she is interviewed by an immigration officer, and must give their reasons for seeking asylum

The immigration officer's report goes to the Home Office to make a decision. If its verdict goes against the person, the immigration service breaks the news.

Anyone denied refugee status has the right to appeal, but must do so within a week of being turned down.

The appeal will be heard by an independent immigration adjudicator, at one of a number of special appeal courts around the country. The adjudicator gives a decision in writing later.

If the appeal upholds the Home Office's refusal, it is an end to most cases and the person should leave the UK.

But a few people win permission from the adjudicator to take their case further, to an immigration tribunal. The official appeals process ends here.

According to the Home Office, the average time taken for cases to go through this process is 13 months.

A handful asylum-seekers who are refused leave to stay want to take their case further still. As the appeals system has run out, they must use the law. Their solicitor will apply to the High Court for leave to seek a judicial review in the Court of Appeal.

The appeals process is laid down by law and cannot by bypassed.

Prosecutions first

But Jack Straw has pledged to ask officials to make the 74 Afghans priority cases, leapfrogging those on the waiting list, and has set a deadline of two months for deciding all cases.

The hostage-takers are believed to be seeking sanctuary from Afghanistan's Taleban regime, which has a known record for persecuting dissidents.

If they do seek refugee status, any application would have to come after any prosecutions have been dealt with.

The hostage-takers may face long prison sentences. Britain takes a tough line on such crimes and previous hijackers have served sentences of up to nine years.

Normally, foreign nationals convicted of crimes in this country would be deported at the end of their jail term. But the UK is obliged, under the United Nations Convention on Refugees, to consider any asylum claim.

If they are to be allowed to stay, each asylum-seeker will need to show a "well-founded fear of being persecuted for reasons of race, religion, nationality or membership of a particular social group or political opinion".

Officials can also take the applicant's credibility into account, considering whether they have lied, produced false documents, or changed their behaviour to increase their chances of getting asylum.

If the Afghans' claims are fast-tracked, it will be a contrast with an earlier, similar case.

Six members of a gang which hijacked a Sudanese passenger jet in 1996 are still living in the UK, awaiting a decision on their claims.

On the other hand, they may be allowed to stay in the UK: in 1982, three Tanzanian hijackers who diverted a plane to London obtained asylum after serving short prison sentences.

One of the three has since become a lawyer specialising in asylum requests.

But Labour MP Robin Corbett, who serves on the Home Affairs Committee, said the hostages would probably find it hard to sustain their claims since they had initially boarded an internal flight.

There has also been speculation that some of the "hostages" were complicit in the hijacking, seeing it as a flight to freedom.

Under the terms of the Immigration and Asylum Act, which comes into force in April, the Afghans will receive food vouchers rather than cash handouts.