Lancashire's council leaders are to submit a bid to government to introduce "targeted" mass Covid-19 testing.
The county is set to move into tier three restrictions when the second national lockdown ends on Wednesday.
However, the area's infection rates vary largely, with Pendle registering 306.1 cases per 100,000 people, while Lancaster recorded 115 per 100,000.
Public health director Dominic Harrison said there would be a sharper focus on testing in areas with high cases.
The government previously said mass rapid testing schemes, which will ask all residents with or without coronavirus symptoms to take a test, would be rolled out to 67 more areas in England.
The scheme was piloted in Liverpool, which is now set to drop down into tier two restrictions after Health Secretary Matt Hancock praised the city's "remarkable" fall in infection rates following its introduction.
'Some Army support'
Areas to the east of the county, including Pendle, Blackburn and Rossendale, reported infection rates of more than 280 per 100,000 in the latest government figures for 25 November, far above western areas, such as Lancaster, Wyre and West Lancashire, where rates fell below 130.
Council leaders had asked for the county to be split into two tiers, reflecting these different rates, but the idea was rejected.
Mr Harrison said the government would formally offer Lancashire "a mass testing option" on Wednesday, which he expected to be a reduced version of Liverpool's model.
He said he expected "some Army support" for any testing regime, adding the county would "do something similar [to] but not the same as Liverpool" and "target some of our mass testing" on groups "where we know the infection rates are highest" such as a ward within a local authority "or a group like the homeless".
He said any testing would "go ahead across the whole of Lancashire, but it will be targeted on the highest risk areas".