The Test and Trace system has recorded its best ever week for contact tracing, hitting its target for only the second time since May, new figures reveal. 

The proportion of “close contacts” of people with Covid in England reached was 92.7% for the week ending December 2, according to the most recent figures. 

Despite running for more than six months, Test and Trace only managed to hit it’s 80% target for the first time since May on December 10 – reaching 85.7% of close contacts of people with Covid-19 in England. 

During one week in October the system only managed to trace 59.6% of contacts. The government’s own scientific advisers have said that the entire system is only viable if it meets the 80% target. 

The key driver for improved performance was the decision only to phone households once when they’ve been in contact with a positive coronavirus case, instead of calling individual household members.

The service had been getting complaints from the public about being “bombarded” with phone calls to the same home and decided in mid-November to change its practices.

Figures in early December were the first time that under-18s in a household were no longer contact traced individually, provided the parent or guardian in the household confirmed they had completed their legal duty to inform their child to self-isolate.

“These operational improvements have resulted in an increase in the proportion of contacts reached and the proportion reached within 24 hours,” the Department for Health and Social Care (DHSC) said.

The budget for Test and Trace is now £22bn, equivalent to almost a fifth of the entire NHS budget for one year, and has faced intense criticism for its use of private sector firms such as Serco and Deloitte. 

Despite significantly expanding its testing capacity, the system’s turnaround times and poor contact tracing has led critics to suggest taxpayers’ money has been wasted on the project.