The prime minister is attempting to demonstrate his commitment to domestic delivery today as he unveils a new asylum initiative.

Taking part in his first public engagement since returning from holiday, Tony Blair will visit Croydon with the home secretary.

They will launch a new project to track asylum seekers as their claims are processed.

Visiting the asylum screening unit, Blair and Blunkett will attempt to divert media attention from the Hutton inquiry.

Downing Street is determined not to become sidetracked from its public service delivery targets.

Blair has set a personal target of halfing the number asylum applications by September.

The Home Office is expected to publish figures this week showing it is on course to meet Blair's pledge.

By moving towards greater tracking of refugees, the government hopes to reduce the number of immigrants who disappear from the authorities' radar having claimed asylum status on arrival in the country.

The idea underpins the controversial asylum centre plans - where applicants will stay until all stages of the process have been completed.

Blunkett said the use of biometric technology, such as fingerprinting and facial screening, will be extended during applications for British visas.

The plan mirrors a similar system being introduced in the United States and is already being piloted for visa applications from Sri Lanka.

"Preventing people from travelling to the UK illegally in the first place has been a key part of the strategy to reduce the number of unfounded asylum applications," Blunkett said.

"Measures including new detection technology and UK immigration controls in France have already stopped 4,000 people in the first half of this year.

"I will be bringing forward new legislation at the earliest opportunity to deal with those who destroy their documents and reduce the opportunity to string out the appeals process.

"But I am also determined we take advantage of new technology to tighten up visa applications.

"Biometrics can play a big part in tackling illegal immigration and abuse of our asylum system and by embracing it we can reduce further the pull factor to the UK.

"Taking a biometric when we are dealing with a visa application will provide a much more secure way of confirming someone's identity, even if they deliberately try to mislead the authorities by destroying their documents."