More than a third of West Midlands hospitals and clinics have still not begun a "deep clean" designed to fight the MRSA superbug, health officials revealed yesterday.

It means they are unlikely to meet the deadline set by Gordon Brown, the Prime Minister, to complete the intensive cleaning process by the end of March.

Speaking at the Labour Party conference last September, Mr Brown pledged that "walls, ceilings, fittings and ventilation shafts will be disinfected and scrubbed clean" in every trust in England which provides beds.

But only 24 of the 38 eligible health trusts in the West Midlands have even started the deep cleans, which take weeks to complete. It leaves 14 - more than one in three - which have not yet started.

Last night NHS West Midlands, the regional health authority, said: "The majority are on course for the end of March."

Trusts which have not yet begun the deep clean include Dudley Group of Hospitals NHS Trust and Heart of Birmingham Primary Care Trust.

The admission came after ministers insisted they were confident the deep cleans would be completed on time.

Health Secretary Alan Johnson said: "We are confident we can do this."

He also denied they were a gimmick, following criticism from opposition MPs and some medical professionals.

Mr Johnson said the aim was to reas-sure the public, who took an "awful lot of interest" in the programme.

He added: "It's not as if we are saying deep cleaning is our total response to healthcare-associated infections."

Critics have included Dame Betty Kershaw, the former president of the Royal College of Nursing, who warned that a deep clean of hospitals would have no significant impact, in an article published by a medical journal last month.

Dame Betty, Emeritus Dean of Sheffield University School of Nursing and Midwifery, said: "The proposed 'deep clean' will be merely papering over the cracks. Cleaning staff need to be employed by the NHS, not contracted out."

Last night West Midlands MP Andrew Mitchell joined the criticism. He said: "This Brown-inspired gimmick will not tackle the problem.

"More local control is the way to raise standards, and less Whitehall publicity-driven diktat."

In an announcement on Monday about disease control, Mr Johnson also called on doctors to stop prescribing antibiotics such as penicillin for coughs, colds and sore throats, because their over-use was causing MRSA to become resistant to them.

He set out how hospital trusts across England should invest the £270 million already announced in the Comprehensive Spending Review for infection control.

He said up to £45 million could be spent on specialist staff, the equivalent of two infection control nurses, two isolation nurses and an antimicrobial pharmacist in every trust.

Health Protection Agency figures in November suggested hospitals in England may be turning the corner on battling the bugs. Cases of MRSA fell by 10 per cent from April to June 2007 compared with the previous quarter. Cases of C diff were also down seven per cent from April to June 2007 compared with the same quarter the previous year.