Food manufacturers have reacted with fury to the FSA's new satfat proposals, which were put out to consultation this week.

The proposed voluntary measures include reducing portion sizes on snacks, expanding the definitions of ice cream and Cheddar to include lower-fat products and reformulating sausages, pies and meat snacks.

While the steps on snacks and dairy were broadly welcomed, the FSA's estimates on the cost to industry of reformulation are believed to be totally unrealistic.

The agency estimated the minimum cost of reformulating products to cut satfat at between £1,000 and £3,000, using this ­figure to generate a "cautious estimate" of £5.2m to reformulate all 1,700 meat pie and pastries in UK stores.

Reducing satfat in the UK's 1,055 sausage SKUs would cost £3.2m, it estimated. The FSA added that, as manufacturers generally carry out reformulation anyway, the direct cost to industry of the proposals would likely be lower.

By contrast, United Biscuits revealed last November it had spent more than £6m and three years reformulating three lines in its biscuit range.

"It costs far more than £3,000 per product to reformulate we'd spend more than that on packaging alone," said one pie maker. "We have to be very careful not to change the taste, and that makes the process expensive. Pies are an easy target, but not necessarily fatty our steak and kidney pies have the same fat content as a piece of salmon," he added.

A director at another manufacturer said the estimates were "simply not realistic", but were better than its salt proposals in October. These suggested cutting salt would come at no cost to industry. He added that in his view the FSA "would not care whether it was £8m or £80m, in any case".

The Food and Drink Federation said the concern of members was compounded by a "Kafkaesque" marketing restriction. The FSA wants to encourage suppliers to promote and market their healthier ranges more aggressively just a month ahead of new European regulations that will outlaw claims such as 'X% less fat', 'no added salt' and 'extra light'.

"Formulating reduced-fat products takes a lot of time, effort and money. Of course manufacturers would like to promote them," said FDF communications director Julian Hunt. "But now they're stuck in the Kafkaesque situation of being told by the FSA to do exactly that, just as new EU regulations which the FSA is leading on in the UK are introduced restricting our ability to do so."