Gordon Brown says the Government has "no plans" to introduce a minimum pricing on alcohol "at this stage".
It came after Health Secretary Andy Burnham told the Daily Telegraph that a minimum price of 40-50p per unit should form part of Labour's election manifesto.
In a statement that shows a clear split over the issue within Government, the Prime Minister's spokesman said: "We have no plans to introduce a minimum price for alcohol. It would not at this stage be sensible."
But he conceded there are "issues around very cheap alcohol in bars, rock-bottom cheap alcohol".
It comes as pressure mounts on the Government to push ahead with minimum pricing the after the influential Health Committee backed the controversial measure.
Burnham is believed to favour an additional levy on alcoholic drinks to ensure supermarkets or drinks producers do not profit from a price rise. The money raised would be used to fund public health campaigns.
He said: "We have never shrunk from taking tough public health decisions and we are not going to start now.
"The mood has changed and there is rising public concern — we need to respond to that and move on the debate. There is no shortage of research that shows the link with price and people drinking harmful levels of alcohol — there is no debate about that."
Conservative health spokesman Andrew Lansley accused Labour of being in a "complete mess over alcohol pricing".
But splits have occurred within Tory ranks too.
The Party's stated policy is to ban below-cost alcohol sales, but Shadow Health Minister Mike Penning told the Morning Advertiser last month: "I've not said I want to ban it. I've said I have a real concern about it."
Meanwhile, the latest version of the mandatory alcohol retailing code is due to be launched by the Home Office tomorrow, with media reports saying a mandatory Challenge 21 policy is set to be included.