A Christian expert on viral disease and vaccines has questioned the government's plans for mass-coronavirus testing.
The multibillion-pound "Operation Moonshot", would see 10 million tests carries out daily at the start of next year.
The Prime Minister told a Downing Street press conference on Wednesday that the scheme could help sport and entertainment venues reopen fully and allow people to socially mix in large groups again with on-the-day tests.
Leaked documents seen by the BMJ medical journal suggested the project could have a price tag of £100 billion - close to that of the £114 billion budget given to NHS England in 2018/19.
Paul Morrison is a Christian and former postdoctoral researcher at Imperial College and studied viral disease and vaccine design.
He told Premier the Government's plans are too ambitious.
"Ten million tests a day is a lot. It is a very large number and it's a very expensive thing to get to. The technology required does not exist, so it's even more expensive to develop that technology.
"Having watched these things being developed in the past, you can throw money at something but that doesn't necessarily mean it's going to work in the end.
"It feels like a very big target and I'm not entirely sure whether or not that is the target we should be aiming at. There might be better ways of spending that money both to stop COVID from spreading and also to promote the well-being of the population who've been hit very hard by Covid."
Also, a leading statistician has warned that hundreds of thousands of people could be unnecessarily told to isolate under the proposals.
But Health Secretary Matt Hancock said he is "absolutely determined that we will get there" and is looking forward to rolling out the programme, which will aim to provide mass testing using saliva and other methods which can deliver results within 20 to 90 minutes.
He explained that the approach is being piloted and steps are being taken to verify the new technology ahead of a desired nationwide roll-out.
Morrison told Premier he'd like to see the government set attainable targets instead of big flashy ones.
"A vaccine is the place we all want to get to. Until there is a vaccine that that really works, then testing, maintaining social distancing, and all the really sensible and boring measures that we have to go through, that's the way to keep it at bay.
"Public health should be boring. Getting to the point where a virus is eradicated or ceases to be a problem is lots of small, dull, incremental steps.
"I think the Government wants to say something big and exciting. You can understand why and it doesn't have to come from a bad place, but big and exciting isn't what's needed. What's needed is hard work and slow, steady progress.
"That has happened at times, but it looks at this moment in time that that progress is starting to go backwards, so we need to refocus on that."
Meanwhile, the number of close contacts of people who tested positive for Covid-19 in England reached through the Test and Trace system fell to its lowest since the system was launched.
Just over two thirds (69.2 per cent) of close contacts were reached in the week ending 2nd September, down slightly from 69.8 per cent in the previous week, and once again short of the Government's 80 per cent target.
Listen to Premier's interview with Paul Morrison here:
