The Conservatives have set out plans to prevent development on top quality farmland, reform the body which delivers EU subsidies to farmers and set up a review of red tape as part of efforts to back British farming.

As politicians attempted to woo the farming vote at the National Farmers’ Union’s annual conference in Birmingham, the Liberal Democrats also set out proposals to improve delivery of subsidies by the discredited Rural Payments Agency and to spend the savings on farm apprenticeships.

Environment Secretary Hilary Benn announced a new voluntary code to improve the country of origin labelling on pork products by supermarkets and restaurants, which he said would help consumers support UK farmers by ending the confusion over whether they were really buying British.

Mr Benn said farmers should vote Labour because the Government had “listened very carefully to the NFU and farmers on a whole range of issues”, and had made progress on many fronts, including voluntary environmental schemes and the implementation of regulations from Brussels.

He said farmers and the Government had a common goal, “a successful, profitable and healthy UK farming industry”, but again came under fire for his refusal to allow a cull of badgers to tackle TB in cattle.

Shadow environment secretary Nick Herbert told the conference the Conservatives were proposing a manifesto for British farming with a set of “practical, deliverable policies” to back UK agriculture, increasing production while protecting the environment.

The Tories’ agenda includes a pledge to reduce the burden of regulation on farming by engaging with the EU to make new sure rules do not damage UK interests and commissioning an industry-led review of red tape within three months of taking power.

Mr Herbert also said UK farmland is a national resource, but that the protection of the best agricultural land has been downgraded under Labour.

He said the Conservatives would introduce new rules into their national planning framework to prevent development of grade 1 and 2 agricultural land except in exceptional circumstances - regulations which would cover more than a fifth of English farmland.

“If we understand the value of farming, we can’t build on the best land,” he said.

He also said there is a growing interest in local food and British produce, and that a Tory government would introduce legislation on country of origin labelling if a comprehensive voluntary agreement could not be reached.

Mr Herbert pledged to prioritise research and development funding within the Department for Environment, Food and Rural Affairs (Defra).

But he said the next government would have to be leaner and more efficient and could not afford the “competing armies of rural bureaucrats”, with 28,000 officials working for 67 quangos under Defra.

He said the Rural Payments Agency, the body which distributes EU subsidies to farmers, had been a “shambles and a disgrace” and would be subject to the cost-saving review of quangos which the Conservative Party has promised if it comes to power.

And he said a Tory government would bring in a fundamental shake-up in which the chairman of the agency would be the farming minister, to take direct responsibility for management of the system.

Putting forward Liberal Democrat proposals to support UK farming, the party’s environment spokesman Tim Farron said the system of paying subsidies in England currently cost £1,743 for each claim - which could be for payments as little as 1p.

Setting a minimum payment level of £300 would save £20 million which could be invested in farm apprenticeships to train up the farmers of the future.

Mr Farron also called for a powerful, proactive food market regulator, warning that Conservative and Labour proposals for a supermarket ombudsman to regulate retailers’ treatment of producers would just provide “cover” for supermarkets.