However, a survey by the Food Standards Agency showed that the majority of consumers were generally unaware of the use of GM animal feed by farmers.

"Once made aware of its use, they typically considered that products from animals fed GM feed should be labelled, consistent with previous FSA research," the study said.

The Food Standards Agency published the findings of the research this week looking at consumer attitudes to the labelling of genetically modified (GM) food and the use of 'GM-free' labelling.

The research carried out by Define Research and Insight from June to September last year showed that consumer awareness of the current labelling requirements is low.

Participants were typically not seeking information or labelling with regard to GM foods and only two per cent of participants mentioned spontaneously that they looked for information about GM content when buying food products for the first time.

The research said that there was a slight preference for labelling indicating the presence of GM, rather than labelling indicating the absence of GM.

The study said that it was felt that labelling foods to indicate the absence of GM ingredients could result in a number of expectationssuch as that a product labelled as ‘GM-free’ was, without realising that GM could have been used in animal feed.

The Food Standards Agency said it commissioned this research to inform discussions within Europe about GM labelling and to ensure the UK public’s views were understood and represented.

At present, some EU countries have introduced schemes where products can be labelled as 'GM-free' or 'without GM'. However, the rules of these schemes tolerate some GM materials (low level accidental presence, use of certain GM additives etc). The UK has not introduced any scheme to indicate the absence of GM. The European Commission is currently considering whether to harmonise these national schemes across Europe.

In the EU, if a food contains or consists of genetically modified organisms (GMOs), or contains ingredients produced from GMOs, this must be indicated on the label. For GM products sold 'loose', information must be displayed immediately next to the food to indicate that it is GM.

Products such as flour, oils and glucose syrups have to be labelled as GM if they are from a GM source.

Products produced with GM technology (cheese produced with GM enzymes, for example) do not have to be labelled.

Products such as meat, milk and eggs from animals fed on GM animal feed do not need to be labelled.