Sage experts say Test and Trace is having a 'marginal' impact on tackling the virus as the system neither tests nor traces enough people – and is too often ignored even when it works

Sage experts say Test and Trace is having a 'marginal' impact on tackling the virus because the system neither tests nor traces enough people. 

The £12 billion programme will 'further decline' unless it grows at the same rate as the epidemic, the scientific advisory group warned in documents released on Monday.

Boris Johnson has promised the scheme would be 'world beating', while experts and politicians alike see it as a major way of reducing the severity of restrictions imposed during the crisis.

'The relatively low levels of engagement with the system... coupled with testing delays and likely poor rates of adherence with self-isolation suggests that this system is having a marginal impact on transmission at the moment,' they wrote.

The criticism, voiced in a summary of a review of measures on September 21, will increase the pressure on Baroness Harding (pictured outside the Health Department last month), the Conservative peer in charge of Test and Trace

Samples are taken at a coronavirus testing facility in Temple Green Park and Ride, Leeds,

'Unless the system grows at the same rate as the epidemic, and support is given to people to enable them to adhere to self-isolation, it is likely that the impact of Test, Trace and Isolate will further decline in the future.' 

The criticism, voiced in a summary of a review of measures on September 21, will increase the pressure on Baroness Harding, the Conservative peer in charge of Test and Trace.

Shadow health secretary Jonathan Ashworth said: 'This is yet further evidence that the Government's incompetence is hampering our response to a second wave.

'Sage have essentially confirmed test and trace is not functioning adequately as we have been warning for months.

'Ministers need to get a grip of testing so we can get control of the virus.'

A couple wearing face masks download the NHS Track and Trace app on their mobile phones while standing next to 'Protect your loved ones. Get the App' digital advert in north London

The scheme's success only seems to have worsened since the Sage document was written.

Figures from last week showed NHS Test And Trace in England had suffered its worst week for the proportion of contacts it successfully manages to track down.

Only 68.6% of close contacts of individuals who have tested positive for Covid-19 were reached in the week ending September 30, the lowest weekly percentage since the scheme began.