The sugar tax applied to fizzy drinks could be extended to pre-packaged milkshakes and lattes under new government plans.
The government is consulting on proposals to end the exemption from the tax for milk-based drinks, as well as non-dairy substitutes such as oats or rice.
Chancellor Rachel Reeves announced in her autumn budget last year that the government was considering widening the levy.
Shadow chancellor Mel Stride labelled the move a "sucker punch" to households when Labour had "already pushed up the cost of living for families".