The supermarket giant has called on the Advertising Standards Authority to force Ocado to shelve the campaign because it claims Ocado is regularly more expensive on at least 500 items, according to The Times.
“We think it's underhand and entirely misleading,” a Tesco spokesman told the paper.
Ocado announced in March that it would match Tesco prices on branded goods, investing about £10m into the commitment.
“We are not surprised that Tesco have decided to act with their customary aggression, but we are disappointed they don't have more important issues to focus on,” said Jason Gissing, Ocado's chief financial officer.
“They have clearly realised that their initial response of price-cutting goods we both sell has not worked,” he added.