Dairy farmers who supply Müller UK & Ireland Group will now be covered by the Voluntary Code of Practice, the company has said.
The first milk supply contract to comply with the code was announced by Arla Foods earlier in the week.
The dairy coalition warned in January that milk buyers must implement the dairy industry code in contracts or face the consequences'.
The coalition, NFU Cymru, the NFU, NFU Scotland, FFA, TFA, WFU and the RABDF also called for further price rises, urgently needed by farmers to be forthcoming, and that companies not complying will be made public.
"It is the responsibility of every milk buyer to ensure the voluntary approach to improving milk contracts succeeds. The alternative is legislation and the coalition will not rest until we see better more balanced contracts for dairy farmers" said Raymond.
NFU Cymru Deputy President Stephen James said, "The coalition has laid down the challenge to David Heath to put his full support and force behind the full implementation of the code."
"As a coalition we are committed to the success of the code and trust the UK Government to be equally committed. That said, we welcome David Heath’s recent challenge to processors, when he told the Dairy UK board, that if contracts do not improve via the voluntary route, the UK Government will look to legislate."
And Müller has reaffirmed its commitment to offering a 'market leading clean' milk price with no member retentions, capital levies, balancing or haulage charges.
"It is right that our members loyalty is earned rather than contractually imposed and we remain happy to be judged by our performance as a company that is ambitious to grow" said Pete Nicholson, Agricultural Affairs Manager for Müller Wiseman Dairies.
"A three month notice period for members of the Müller Wiseman Milk Group has been a central part of the contract we offer to those not aligned to major supermarket customers, for almost 20 years.
"We now urge the rest of the dairy industry to follow suit. It is our hope that the Voluntary Code will be the stimulus required to break the log jam allowing those farmers who wish to move, the means to do so within a reasonable timeframe."