By Nick Triggle
Health reporter, BBC News
The government is within touching distance of hitting its MRSA target, but opposition parties have accused ministers of manipulating the data.
Hand washing is thought to be the best way to tackle MRSA
Latest figures show there were 1,072 cases of the superbug in England from July to September last year.
This approaches the target of half the 1,925 average quarterly 2003-4 figure.
But the Tories and Lib Dems accused ministers of moving the target back so it takes account of the period directly after the £50m deep clean of hospitals.
The latest quarterly figure represents an 18% fall on the previous quarter and comes after steady falls since September 2006. Decreases have also been seen elsewhere in the UK.
In 2004, the then health secretary, John Reid set a target of halving the rates by March 2008.
But last year a leaked Department of Health memo suggested the goal was likely to be missed.
But the precise details of the target were never set out at the time and the government has now told the BBC News website it will consider it met if there are 963 cases or less in the quarter April to June.
Shadow health secretary Andrew Lansley said: "It appears the government are selectively choosing data to try and fix an outcome.
"It's no coincidence that the time frame they selected is after hospitals finish their deep clean programme."
Lib Dem health spokesman Norman Lamb said: "This is disturbing evidence of the government manipulating figures to hit a target.
"By shifting the numbers around in this way, they are far more likely to hit a target which had previously seemed out of reach."
But the government denied manipulating the figures.
A spokesman said it always planned to use the April to June period to assess if the MRSA target had been met to give hospitals every opportunity to bring in measures before the end-of-March deadline.
Health Secretary Alan Johnson said: "First the Tories say our deep clean is a gimmick and now they say it will help us achieve our target for cutting MRSA rates.
"Rather than trying to score political points they should back our tough action and extra investment to tackle infections and improve cleanliness."
He added: "These figures demonstrate that the tough and sometimes controversial measures which this government is taking are having a real impact on rates of infection, cleanliness and on the safety of patients."
The latest hospital infection figures from the Health Protection Agency also showed that Clostridium difficile rates were falling.
There were 10,734 cases of C difficile in patients aged 65 and over in England between July and September 2007.
This was a 21% decrease on the previous quarter, when 13,669 cases were reported, and a 16% drop on the same period in 2006.
The government has set a target of reducing C difficile by 30% over the next three years.
Murray Devine, head of safety at the Healthcare Commission, which inspects hospitals on infection, prevention and control, said: "MRSA is clearly moving in the right direction and the signs on C difficile are encouraging.
"However, in both cases there are too many people suffering from these infections. It is terribly important that trusts maintain the pressure."