Ministers have promised to listen to calls to give a new supermarket watchdog the power to mete out hefty fines to protect producers from "sharp practices".
Proposed legislation to create an adjudicator to oversee a groceries industry code of practice, backed by Westcountry farmers, has climbed a significant parliamentary hurdle and is poised to be in place next year.
But MPs have warned the new figurehead needs "real teeth", and fear its principle power to "name and shame" badly behaving retailers will be inadequate.
Politicians from across the political spectrum are united in demanding the watchdog can issue financial penalties, though the Government has refused to give ground.
However, Farming Minister David Heath, Liberal Democrat MP for Somerton and Frome, said the Government was prepared to listen to MPs about the need for fines.
He told MPs in the Commons as the Groceries Code Adjudicator Bill received an unopposed second reading: "Let us discuss what the effective sanctions are. Let us make sure we have got it right.
"The Government believes it has got it right at the moment. Of course we will listen to what every member has to say on this issue and make sure we have legislation that is fit for purpose."
A code of practice to stamp out supply chain bullying was introduced in 2010, but has been described as "a game of rugby without a referee" without a watchdog in overall charge.
During the debate, MPs gave unqualified support to the creation of an adjudicator but urged ministers to give it more clout.
Camborne and Redruth Conservative MP George Eustice, who worked at his family's West Cornwall strawberry farm for a decade, outlined "sharp practices" he experienced.
He said: "Growers were frequently forced to participate, often unwillingly, in supermarket promotions, and were expected to sell their produce for below the market rate."
He added: "The groceries code adjudicator is more likely to succeed if the power to fine is there from the beginning and more likely to fail if it is not."
Neil Parish, Conservative MP for Tiverton and Honiton, also a former farmer, said: "The Bill will need to have real teeth.
"It is a great idea to name and shame retailers, but we need to have the powers to fine them and to keep fining them. If they do not adhere in the first instance, there must be real pain, by which I do not mean tuppence ha'penny from the billions of pounds of turnover; the fine has to mean business."