About 10,000 litres of milk have been sent to EU Agriculture Commissioner Mariann Fischer Boel in the last two weeks.

"Unfortunately, a lot of the milk had gone off and some of the cartons had burst," said an unnamed Commission official.

"So it was all a bit smelly and messy."

Rather than throw away milk that is worth next to nothing, they came up with the novel idea of posting it to the EU Commission as a way of drawing attention to their plight.

"We have to, unfortunately, throw it away," said Michael Mann, spokesperson for Commissioner Boel.

"We are conscious of their concerns, but we don't think it's a good idea and they should send it to a good cause."

World prices for milk have risen -- but this has not translated into higher prices for German farmers, one reason why they went on strike in May.

During the dispute they fed milk to calves in public and poured it on fields as fertiliser.

As a result, the supermarket chain Lidl raised milk prices.

The latest protest has been prompted by the EU's decision in April to raise milk quotas by 2% to curb rising prices and meet growing demand.

Boel has pleaded with the farmers to find a better way to demonstrate their anger.

"If you would like to keep on sending milk, I can suggest that it would be better put to a good use in your local area," she said.