The Healthcare Commission will this week begin conducting spot checks of acute trusts to ensure that they are adhering to the government's hygiene code.

The inspection programme, which will see all 172 acute trusts scrutinised over the next 12 months, has been established at the request of health secretary Alan Johnson.

Commission chief executive Anna Walker said previous inspections had shown most trusts were working hard. But she warned if they fell short "we will use our powers to ensure improvements are made".

In a letter to acute chief executives, including foundation trusts, Ms Walker explains that the commission has already identified the 25 trusts which will be inspected between now and June. They have been asked to send documentation to the commission, but they will not be told the precise date of the inspection. The next wave of trusts will be contacted after June.

Inspections are likely to last one to two days. They will assess the hospital site and facilities and interview staff. Each year inspections will focus on different aspects of the hygiene code, launched in October 2006. This year cleanliness, isolation facilities and management systems will be under the spotlight.