PERFORMANCE: The troubled primary care trust was ranked 147th in the country for coverage, testing only three per cent of the targeted population.

Documents released by NHS London under the Freedom of Information Act revealed the figure for quarter two of 2010-11, and said 3.4 per cent of those tested had been positive.

The paper said: “The quality of services [across the capital] remains extremely variable in terms of positivity rate, the proportion of people diagnosed with Chlamydia that are treated and partner notification and treatment.

“There is a stark contrast in the quality and range of services provided with sometimes limited provision for adults over the age of 21, reflecting the emphasis to date on reducing teenage pregnancy.”

In 2009-10 London’s coverage of 26 per cent exceeded the national target of 25 per cent. The target for 2010-11 is 35 per cent.

In 2009-10 Harrow spent £140,100 on its Chlamydia programme and performed 4,144 tests, the third lowest in London.

The PCT average spend across the capital was £410,000.