Lib Dem MEP Liz Lynne aims to travel to the European Parliament in Strasbourg on Monday carrying prime cuts of Herefordshire beef in a Union Jack bag.

"If French officials wish to prevent a democratically-elected member of the European Parliament entering France with perfectly safe British beef then so be it," she said.

"This will highlight the ridiculous nature of this illegal ban on our beef."

The BBC's Richard Wilson: "As yet there are no signs of a widespread boycott"

The move comes as supermarket chain Sainsbury's launches a national advertising campaign to show its support for British beef, but refuses to join a growing boycott of French produce.

An EC decision will be made next week

Tesco has reported a drop in sales of French dressing, fresh French produce and Dijon mustard, and has cancelled a £2m order for French mistletoe this Christmas.

Asda said it was taking French brie cheese and French bread off its shelves, while Budgens and Somerfield have launched a boycott of French apples and pears.

The UK Government has said it will not boycott French meat, despite a European Union report which said that some French farmers have used sewage to make animal feed.

The Commission has given France until 28 October to come up with suggestions to supervise its rendering plants.

France argues that since the waste is being heat-treated, the resulting matter is safe and can no longer be considered sewage sludge.

Agriculture Secretary Nick Brown described the practice as "horrible and disgusting" but said it was a matter for the European Commission to resolve.

Agriculture Minister Nick Brown: "There is no protectionist solution to this"

The disclosure caused particular fury among UK farmers because of the French ban, imposed because the country believes British beef is not yet BSE-free.

EU scientific experts are due to meet in Brussels on Monday to consider for a second time a vast dossier of evidence on British beef from the French Food Safety Agency.