Speaking at the Oxford Farming Conference, the shadow agriculture secretary, Kerry McCarthy said that too many farmers are struggling to make a decent living.

Or, she said, they are caught in a Catch 22 situation relying on basic payments but struggling with bureaucracy and paperwork.

“From my perspective, one of the biggest problems is that you are being forced to operate in a broken market,” she told farmers at the conference.

“If the market was working, our dairy farmers would not be forced to accept a price below their cost of production or watch helplessly as prices fall still further.

“Pig farmers would not judge a good day by how much they managed to minimise their loss when selling to the supermarkets.”

However, Ms McCarthy said that in a global market much is beyond the control of governments and the farming sector.

She said the Chinese market has contributed to falling commodity prices and the Russian trade ban has hit prices across the whole of the EU.

“We can look at how power is distributed within the market and the unequal relationships between producers and purchasers,” Ms McCarthy said.

“Supermarket price wars are great for the customers, but it is too often the farmers who are paying the price.”

Ms McCarthy called for the role of the Grocery Code Adjudicator to be strengthened, with her role covering the whole of the supply chain from farm to checkout.

And she said the GCA needs to be able to initiate her own investigations.

The shadow environment secretary called for more British produced food to find a place on domestic supermarket shelves and she said that it was wrong that farmers had to look to export markets because they could not sell their produce at home.

“In 2014 we imported £8.7 billion of fruit and vegetables and £6 billion of meat,” she said.

“We need to promote home advantage, not least by improving food labelling so customers can choose to buy British or local produce.

“With the UK’s food self-sufficiency down to 60 per cent from 75 per cent and our imports of indigenous food increasing, we need to work with the supermarkets to make sure British food is on the shelves.”

Ms McCarthy said that the farming sector could be made more competitive by ensuring basic payments are not delayed.

She also called for a stronger connection between the consumer and the producer – bring the “fork closer to the farm”.

“With the dairy industry, for instance, I think a lot of the public is uneasy about the idea of their milk coming from a mega dairy – wanting assurances on animal welfare and environmental sustainability,” she said.

She said support has to be given to the farming sector to boost the role of research and development to reduce farmers’ costs and increase competitiveness.

She said there needs to be more research to improve yield consistency and breed-in resilience, a more scientific approach to the threat of plant and animal diseases.

However, she added that there is no point in improving the industry’s competitiveness and finances if sustainability is ignored or action is not taken to reduce the costs associated with environmental degradation.

“For better and worse, farming and the environment are inextricably linked,” Ms McCarthy said.

“It is a connection that is all too often overlooked, although not by the industry itself.”

She added: “Our changing climate threatens your crop yield, your water supply and your land.”

Ms McCarthy also called for a leaner, meaner and greener Common Agricultural Policy and also reforms to stop farmers being penalised when they are managing the land responsibly.