A second immigration removal centre holding hundreds more failed asylum seekers is to be built at Gatwick.

The facility, to be constructed within the airport's boundaries, will create 420 new places for illegal immigrants awaiting deportation.

The move forms part of the Government's strategy to step up removals by fast-tracking asylum claims and controlling applicants more closely.

It will increase the capacity of the Home Office's detention estate even after the closure of 265-bed Oakington, in Cambridgeshire, later this year.

Home Office Minister Tony McNulty said: "We are working hard to promote alternatives to detention for example, encouraging more people to return voluntarily and exploring other ways of maintaining contact with individuals through electronic monitoring.

"However, in certain cases detention may be the most appropriate option.

"This new unit at Gatwick will help ensure that we can continue to detain individuals where necessary to protect the integrity and effectiveness of immigration controls."

Gatwick already has an affiliated removal centre at nearby Tinsley House, which can hold 137 detainees.

That centre was opened in 1996 by BAA Lynton, which will also develop the new Gatwick detention facility.

Planning permission is to be sought shortly in the hope of opening the additional centre in 2008.

Mr McNulty added: "Removing those who have no right to remain in the UK is an integral part of our balanced approach to asylum and immigration, helping us to cut abuse of the system and ensure an efficient end-to-end process.

"The latest figures show that our five year strategy on asylum and immigration is taking effect asylum applications are at their lowest level since 1994 and removals are on the increase.

"But we recognise that we need to do more to ensure that the public has confidence in a system that is both robust and fair."