Experts are confident the new scheme can work because dogs have already successfully been trained to detect cancer, malaria and Parkinson's disease.
Respiratory problems - a feature of Covid-19 - are known to cause subtle changes to the body's odour.
Research indicates that dogs can be trained to detect the odour of disease at the equivalent dilution of one teaspoon of sugar in two Olympic-sized swimming pools of water.
The initial phase of the trial will involve NHS staff in London hospitals collecting odour samples from people who are infected with coronavirus, as well as those who are not infected.
The six dogs will then be trained to identify the virus from the samples.
The ability of infected people to transmit the virus before they develop symptoms is one of the key factors thwarting efforts to stifle the coronavirus pandemic.
Lord Bethell, the minister for innovation, said: "Bio-detection dogs already detect specific cancers and we believe this innovation might provide speedy results as part of our wider testing strategy.
"Accuracy is essential so this trial will tell us whether 'covid dogs' can reliably detect the virus and stop it spreading."
The trial is being backed by half a million pounds of Government funding.
The dogs pioneering the research were named last night as Norman, Jasper and Asher, all cocker spaniels; Storm and Star, the Labradors; and Digby, a labradoodle.
When trained, each could screen up to 250 people per hour, the Government said.
The work is not without risk. Yesterday a minister in the Netherlands announced that a dog and three cats had been infected with coronavirus.
The Department of Health said the dogs would only be deployed "if backed by strong scientific evidence".
Dr Claire Guest, the co-founder and chief executive of Medical Detection Dogs, which trains dogs and is taking part in the project, said: "We are sure our dogs will be able to find the odour of Covid-19 and we will then move into a second phase to test them in live situations, following which we hope to work with other agencies to train more dogs for deployment.
"We are incredibly proud that a dog's nose could once again save many lives."
Prof James Logan, who is leading the research at LSHTM said: "Our previous work has shown that malaria has a distinctive odour and, with Medical Detection Dogs, we successfully trained dogs to accurately detect malaria.
"This, combined with the knowledge that respiratory disease can change body odour, makes us hopeful that the dogs can also detect Covid-19."
Prof Logan added: "If successful, this approach could revolutionise how we detect the virus, with the potential to screen high numbers of people."