Home Secretary Jacqui Smith is set to announce a government climb down over the retention of DNA data on the Police national database, paving the way fort the destruction of records on 850,000 innocent people.

She is to launch a consultation on proposals to limit the database to records of those who have been convicted and those suspected of involvement in sexual or violent crimes.

The government has been forced to act by a ruling by the European Court of Justice and is expected to propose a system similar to that in Scotland where records of suspects in crimes involving sex or violence are kept for up to five years.

Details of the consultation are expected on later today. Smith, who has previously strongly defended the retention of the data, said she still believed that the DNA database helped in the fight against crime and bring offenders to justice.

But she added: "There has to be a balance between the need to protect the public and respecting their rights.

"Based on risks versus benefits, pur view is thast we can now destroy all samples."

The climb down follows the Home Office abandoning plans for a national database on communications and internet traffic data, with a requirement for more information to be kept by Internet Service Providers instead.

The DNA database decision follows mounting pressure from the Tories, the Liberal Democrats and civil liberties groups. It is unlikely to affect the retention of data on those who have been convicted, however minor the offence.

The European court criticised the "blanket and indicriminate nature" of current police practice in a ruling last December.