The 23-year-old, who has appeared in the colours of Evo-Stik League Premier side Rushall Olympic and National League outfit Solihull Moors so far this season, has linked up with the Pilgrims following Ben Middleton's recall to parent club, league rivals Harrogate Town.
Middleton, 22, was set to spend a second month on loan with the Pilgrims — but has been recalled by manager Simon Weaver just six days after signing an extension.
Atkinson is eligible to make his United debut in tomorrow's home clash against Blyth Spartans.