Originally the winter supplement was scheduled to run until the end of February, but it has rolled its financial assistance out until 17 April "to help [farmers] cover their production costs".
Commercial director for fresh foods and commodities Matt Simister said: "We recognise that it is a particularly challenging and uncertain time in the global dairy market, which is why over the past six months, we have provided additional financial support to help our First Milk farmers.
"With the effects of the winter still being felt across the country, we are delighted to announce we have extended the supplement."
Mike Gallacher, First Milk’s chief executive, added: "Consumers clearly want their retailers to pay sustainable prices for British dairy products - in both cheese and milk – and Tesco, under Dave Lewis, have taken a leadership position. They deserve a great deal of credit for continuing to support British farmers who supply the milk that makes Tesco’s cheese."