Mass testing will be a "missed opportunity" to get Liverpool "out of the mess it's in" if more is not done to get the less well-off to take part, a senior doctor has said.
Liverpool Medical Committee secretary Dr Rob Barnett said those in the city's deprived areas were "more reluctant" to be tested for fear of losing income.
A mass Covid-19 voluntary testing trial began in the city on 6 November.
The Department of Health said it would be evaluated before further roll outs.
Over 200,000 people in Liverpool have been tested since the pilot began and the city council said 800 asymptomatic cases have been picked up.
The latest figures show that Liverpool's infection rate was 174.3 per 100,000 people in the week running up to 20 November, down from 281.7 per 100,000 seven days earlier.
'Prevent and reduce'
Dr Barnett told BBC Newsnight that uptake for tests was much higher in the city's well-off areas with an affluent area like Woolton seeing "three times the number of people" take part that the "more deprived" areas such as Norris Green or Croxteth had.
He said that was because in "the more deprived areas, the consequence of having a positive test could be a lot more devastating".
"I understand there are various support mechanisms, but that never replaces the income that you will have had if you'd been at work."
If people on a low income are asked to self-isolate by NHS Test and Trace, they can currently claim for a one-off payment of £500 from the local authority.
Dr Barnett said the location of test sites could also be hindering uptake and he was not sure "that someone who has to get two buses to a site is actually going to make the effort".
Mass testing could therefore become "a missed opportunity", he said.
"There is no doubt if you compare the figures to the figures three to four weeks ago, Liverpool is in a much better place.
"But the figures are... still too high [and] we've got too many people in hospital.
"If we can't get more people tested, if it is only the worried well in affluent areas who go to be tested, then actually we won't do what's needed to get the city out of the mess it's in."
A spokesman for the Department of Health said the aim of the testing programme was "to protect those at highest risk and find asymptomatic cases to help prevent and reduce transmission".
"The Liverpool whole-city testing pilot is continuing, and an evaluation will inform the potential roll out... to other areas."
He added that 24 test sites were in use across the city, alongside a "home test delivery service", and anyone who was told to self-isolate by NHS Test and Trace could apply for the support payment "if they meet the other eligibility criteria".