The home secretary will no longer be able to impose tight restrictions on asylum seekers when they appeal decisions against them, after a court judgement ended the system with immediate effect.

The high court ruled the system was unlawful and put asylum seekers "at a serious procedural disadvantage" two weeks ago but disappointed campaigners by granting a stay on the order because it would be "inconvenient" to stop the system while the government appealed.

Campaigners themselves appealed that decision today and the court of appeals ruled in their favour, meaning the fast-track system must be brought to an end immediately.

The move is a major triumph for asylum seekers and their supporters, with many claiming the fast-track system prevented them having the time to put together a case – or access to the evidence they might need to do so.

Many felt this purposefuly stacked the odds against them in a bid to cut the number of people successfully claiming asylum in Britain.

Detention Action director Jerome Phelps said:

"We are delighted that asylum-seekers will no longer face a detained appeals process that is so unfair as to be unlawful. It is unfortunate that it has taken so many court rulings to finally suspend this deeply flawed process.

"People seeking protection from war and persecution deserve better from British justice. We hope that the government will take this opportunity to reflect and develop a different approach that is fair."

The fast-track procedure has now been found to be unlawful three times by British courts, but this is the first time the home secretary has not been able to ignore the ruling and keep on using it.

Authorities argue the detained fast-track procedure – which can be applied to anyone, from any country, regardless of the strength of their case – streamlines and speeds up the asylum process, but figures show very few asylum seekers succeed in their cases once they are on it.

The government is expected to appeal the decision.