Ministers believe it may be due to tougher border controls enforced in Calais under an Anglo-French agreement.

UK officers can check documents of passengers travelling to the UK and check for stowaways inside vehicles.

Separate figures showed the number of immigrants allowed to settle in the UK rose by 20% in 2003 to 139,675 people.

'Chaotic'

Provisional data for April, May and June suggests asylum applications, excluding dependants such as spouses and children, also dropped by 11% to 7,920.

The number of failed asylum seekers being deported from the UK was also down, with 3,725 including dependants removed from the UK.

But Tory home affairs spokesman Humfrey Malins told BBC Radio 4's Today programme: "This government has had a chaotic and shambolic policy for the last few years. They are hopelessly inefficient.

"If there are fewer asylum applications in the last quarter, most people believe that that could mean greater numbers of people are still entering the country illegally, because our borders are not secure, and simply not bothering to claim asylum."

That attack prompted Immigration Minister Des Browne to suggest the Tories were happy to rely on the figures only while they showed an increase in asylum applications even thought they were "prepared in exactly the same way by exactly the same officials".

For the Liberal Democrats, Mark Oaten criticised the government's whole approach to asylum.

"I think that having a target or being obsessed by numbers is just the wrong way to look at this," he told the Today programme.

"For example, I would actually welcome in some circumstances an increase in asylum applications.

"If there was a disaster in Somalia or Iraq, surely we would want to see an increase because it would mean that we were taking people who were fleeing persecution.

"So having this kind of fall may be absolutely meaningless because it could actually be a result of poor information, bad decisions being taken."

Keith Best of the Immigration Advisory Service accused the government of having a "blunderbuss approach" to asylum that in some cases had made applicants destitute.

Sir Andrew Green of Migrationwatch UK said it was "yet another spin operation" by the government and argued the fall in asylum applications to the UK was less than that in the EU generally.

"Immigration figures issued today show a sharp increase in settlement of 20% in 2003 compared to 2002. Grants for settlement are now at their highest recorded level at 140,000 in 2003 - more than double the 1997 figure of 59,000," he added.

Peak in 2002?

On Tuesday, the Home Office released figures on the second quarter of this year and finalised annual statistics for 2003.

Previously released figures had shown that in the first three months of 2004, applications were down 20% on the last quarter of 2003.

Initial figures for 2003 indicate that asylum applications excluding dependants fell 41% to 49,370 on the previous year.

The peak in the number of asylum seekers was reached in the fourth quarter of 2002, when more than 22,000 people applied.

A cause for celebration?

But critics say the number of deported asylum seekers should be taken into consideration, and that others might be working illegally in the UK.

Habib Rahman, the chief executive of the Joint Council for the Welfare of Immigrants, said that asylum seekers might be driven underground by the UK's "increasingly harsh asylum system", which entails detentions and forcible deportations.

"The fact that millions of people worldwide continue to suffer under repressive regimes, yet do not claim asylum in the UK, is not necessarily a cause for celebration," Mr Rahman said.

"Any fall in asylum applications in the UK would reflect an overall trend among the world's 29 industrialised nations.

"International humanitarian initiatives, to which the UK has contributed, have helped that reduction."