David Blunkett will launch a crackdown on failing police forces this week and set out plans to take over units that are not up to scratch.

The Home Secretary con-demned detection rates as "appalling" yesterday and said he would bring in Home Office hit squads to take on police units that have persistently low rates.

Mr Blunkett will announce a big rise in the number of special constables ­ civilian wardens ­ to patrol the streets in a Government White Paper on the reform of the police to be published this week.

He will set in place changes to allow the Home Office to see league tables of police performance but these will not be made public.

The Home Secretary said in an interview with The Observer that "detection and conviction rates are appallingly low. Detection is down to 24 per cent and conviction is down to nine per cent." He will announce an extra 5,400 uniformed officers by spring 2003 and the addition of hundreds more civilian staff, including secretaries, to help police work through mountains of paperwork.

A new breed of "super-bobbies" will be paid a bonus of £3,000 to stay on the beat. Mr Blunkett plans to bring in managers to run failing police units to instil "new thinking". The reforms will allow the Home Office Standards Unit and Her Majesty's Inspector of Constabulary to take over the worst police units.

"There is a big missing factor on the liberal left and that is that we have forgotten crime and disorder and the misery that this brings," said Mr Blunkett.

"We have often quite rightly talked about education, health and the minimum wage. But we haven't said the thing that really bedevils people in the most disadvantaged areas is crime."

A top priority for the Home Secretary will be to tackle the discrepancy in detection rates across the country but Mr Blunkett's reforms are likely to put him on a collision course with senior police officers.